RESUMO
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: Mastitis is one of the major diseases in dairy cattle, as it causes great economic losses to producers due to the reduction of milk production and changes in the quality of the product. The disease is mainly caused by bacteria of the genus Staphylococcus spp., these microorganisms can express various virulence factors, such as biofilms for example. In herds with organic management, producers and technicians use unconventional ways to treat and control the disease, such as homeopathy. However, it is not known if this type of treatment is able to control pathogenic bacteria such as those of the genus Staphylococcus, of relevance to animal and human health. Thus, the objective of this study was to investigate the production of biofilm in vitro and its genes by Staphylococcus spp. isolated in the milk of cows treated with homeopathy, as well as the persistence of microorganisms in animals. METHODS: Ninety-nine isolates of Staphylococcus spp. from cows treated and not treated with homeopathy were identified by internal transcribed space-polymerase chain reaction and investigated for the presence of the icaABCD, bap, aap, atlE, and bhp genes and in vitro biofilm production using the adhesion method on polystyrene plates. The enzyme restriction profile was determined by Pulsed-Field Gel Electrophoresis. Clusters of S. aureus and S. epidermidis with three or more isolates had an isolate selected for Multilocus Sequence Typing. RESULTS: The frequency of S. aureus isolations was similar in treated and untreated cows, while 71.4% of the coagulase-negative identified were isolated in cows treated with homeopathy. The distribution of the operon ica genes was similar in animals with and without treatment, except for the icaD gene, more frequent in treated cows. Production of biofilm was associated with presence of one or more genes from the icaADBC operon. S. aureus revealed a greater diversity and greater dissemination in cows treated and not treated with homeopathy. Sequence Types ST1, ST5, and ST126 were identified in S. aureus. CONCLUSIONS: The presence of biofilm-associated genes and the in vitro production of biofilms, combined with the persistence of clonal profiles of Staphylococcus spp. demonstrate other forms of control for bovine mastitis should be researched for organic production herds.
Assuntos
Doenças dos Bovinos , Homeopatia , Mastite Bovina , Infecções Estafilocócicas , Animais , Biofilmes , Bovinos , Feminino , Homeopatia/veterinária , Humanos , Mastite Bovina/microbiologia , Mastite Bovina/terapia , Leite/microbiologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus/genética , Staphylococcus aureus/genéticaRESUMO
Staphylococcus aureus and coagulase-negative staphylococci (CoNS) have become the main causative agents of medical device-related infections due to their biofilm-forming capability, which protects them from the host's immune system and from the action of antimicrobials. This study evaluated the ability of RNA III inhibiting peptide (RIP) to inhibit biofilm formation in 10 strains isolated from clinical materials, including one S. aureus strain, two S. epidermidis, two S. haemolyticus, two S. lugdunensis, and one isolate each of the following species: S. warneri, S. hominis, and S. saprophyticus. The isolates were selected from a total of 200 strains evaluated regarding phenotypic biofilm production and the presence and expression of the ica operon. The isolates were cultured in trypticase soy broth with 2% glucose in 96-well polystyrene plates containing catheter segments in the presence and absence of RIP. The catheter segments were observed by scanning electron microscopy. The results showed inhibition of biofilm formation in the presence of RIP in all CoNS isolates; however, RIP did not interfere with biofilm formation by S. aureus. RIP is a promising tool that might be used in the future for the prevention of biofilm-related infections caused by CoNS.
RESUMO
Many infants are nurtured with milk supplied by human banks, whose bacteriological and physical-chemical profiles are a major issue. We investigated the bacteriological and physical-chemical characteristics, as well as genotypic and phenotypic and profiles of Staphylococcus species isolated from 240 samples of breast milk from a bank in a teaching hospital. Dornic acidity of milk revealed that 95.4% (229/240) had acceptable limits (< 8.0 oD). Caloric intake showed a wide variation in cream content (4%), fat (4%) and energy values (559.81 Kcal/L). Staphylococcus (105/186 or 56.5%) and Enterobacter (25/186 or 13.4%) were the most prevalent genera, although other microorganisms were identified, including Klebsiella pneumoniae and Pseudomonas aeruginosa. Amoxicillin/clavulanic acid (125/157 or 79.6%), vancomycin (115/157 or 73.2%), and cephalexin (112/157 or 71.3%) were the most effective antimicrobials. High resistance rates of isolates were found to penicillin G (141/157 or 89.8%), ampicillin (135/157 or 86%), and oxacillin (118/157 or 75.2%). Multidrug resistance to ≥ 3 antimicrobials occurred in 66.2% (123/186) of the isolates. Residues of microbial multiplication inhibitory substances were found in 85% (204/240) of samples. Among the coagulase-positive-CPS and negative-CoNS staphylococci, the mecA gene was detected in 53.3% (8/15) and 75% (30/40), respectively. Genes sea, seb and sec were detected in 20% (3/15) of CPS, while tsst-1 was detected in 13.34% (2/15). In addition, 13.3% (2/15) of S. aureus were toxin-producers. Genes sea, seb and sec were detected in 90% (36/40), 5% (2/40) and 15% (6/40) CoNS, respectively. Enterotoxin production was identified in 5% (2/40) of CoNS. The identification of multidrug-resistant bacteria, staphylococci species toxin-producers harboring methicillin-resistance genes, and residues of microbial multiplication inhibitory substances reinforce the need for a continuous vigilance of milk quality offered to infant consumption by human banks.
Assuntos
Leite Humano , Infecções Estafilocócicas , Animais , Antibacterianos/farmacologia , Coagulase , Feminino , Hospitais de Ensino , Humanos , Testes de Sensibilidade Microbiana , Leite , Staphylococcus/genética , Staphylococcus aureusRESUMO
Staphylococcus aureus and coagulase-negative staphylococci (CoNS) have become the main causative agents of medical device-related infections due to their biofilm-forming capability, which protects them from the host's immune system and from the action of antimicrobials. This study evaluated the ability of RNA III inhibiting peptide (RIP) to inhibit biofilm formation in 10 strains isolated from clinical materials, including one S. aureus strain, two S. epidermidis, two S. haemolyticus, two S. lugdunensis, and one isolate each of the following species: S. warneri, S. hominis, and S. saprophyticus. The isolates were selected from a total of 200 strains evaluated regarding phenotypic biofilm production and the presence and expression of the ica operon. The isolates were cultured in trypticase soy broth with 2% glucose in 96-well polystyrene plates containing catheter segments in the presence and absence of RIP. The catheter segments were observed by scanning electron microscopy. The results showed inhibition of biofilm formation in the presence of RIP in all CoNS isolates; however, RIP did not interfere with biofilm formation by S. aureus. RIP is a promising tool that might be used in the future for the prevention of biofilm-related infections caused by CoNS.
Assuntos
Staphylococcus aureus/isolamento & purificação , Biofilmes , Peptídeos , RNA , Microscopia Eletrônica de Varredura , Coagulase , CatéteresRESUMO
Coagulase-negative staphylococci (CoNS) may be considered contaminants when isolated from clinical specimens but may also be a cause of true infection. This study aimed to compare the clonality and SCCmec type of a collection of CoNS isolated from blood cultures of inpatients, nasal swabs of healthy individuals, and patients with chronic wounds, all from the same community, using SCCmec typing, pulsed-field gel electrophoresis (PFGE), and MLST. Staphylococcus epidermidis, exhibited high clonal diversity, but hospital and community clusters were observed. Nosocomial S. epidermidis clones belonged to sequence types ST2, ST6, and ST23. Some Staphylococcus haemolyticus clones were found to circulate in the hospital and community, while Staphylococcus saprophyticus exhibited very high clonal diversity. Staphylococcus lugdunensis, Staphylococcus warneri, and Staphylococcus capitis revealed several isolates belonging to the same clone in the hospital and community. The detection of different SCCmec types within the same cluster indicated high diversity. S. epidermidis was associated with SCCmec I and III, S. haemolyticus with I and II, S. capitis with type V, Staphylococcus hominis with mec complex type A and ccr1, and S. warneri and S. saprophyticus with SCCmec I. The generation of elements and new combinations of cassette genes were highly associated with CoNS isolates, suggesting that SCCmec may not be a good marker of clonality in these bacteria.
Assuntos
Staphylococcus epidermidis , Infecções Bacterianas , Staphylococcus haemolyticus , Staphylococcus lugdunensis , Staphylococcus saprophyticus , Staphylococcus capitis , Eletroforese em Gel de Campo Pulsado , Coagulase , HospitaisRESUMO
The increasing rates of nosocomial infection associated with coagulase-negative staphylococci (CoNS) were the rationale for this study, aiming to categorize oxacillin-resistant CoNS species recovered from blood culture specimens of inpatients at the UNESP Hospital das Clínicas in Botucatu, Brazil, over a 20-year period, and determine their sensitivity to other antimicrobial agents. The mecA gene was detected in 222 (74%) CoNS samples, and the four types of staphylococcal chromosomal cassette mec (SCCmec) were characterized in 19.4%, 3.6%, 54.5%, and 14.4% of specimens, respectively, for types I, II, III, and IV. Minimal inhibitory concentration (MIC) values to inhibit 50% (MIC50) and 90% (MIC90) of specimens were, respectively, 2 and >256µL/mL for oxacillin, 1.5 and 2µL/mL for vancomycin, 0.25 and 0.5µL/mL for linezolid, 0.094 and 0.19µL/mL for daptomycin, 0.19 and 0.5µL/mL for quinupristin/dalfopristin, and 0.125 and 0.38µL/mL for tigecycline. Resistance to oxacillin and tigecycline and intermediate resistance to quinupristin/dalfopristin were observed. Eight (2.7%) of all 300 CoNS specimens studied showed reduced susceptibility to vancomycin. Results from this study show high resistance rates of CoNS to antimicrobial agents, reflecting the necessity of using these drugs judiciously and controlling nosocomial dissemination of these pathogens.
Assuntos
Antibacterianos/farmacologia , Coagulase/metabolismo , Farmacorresistência Bacteriana/genética , Infecções Estafilocócicas/microbiologia , Staphylococcus/efeitos dos fármacos , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana/efeitos dos fármacos , Genes Bacterianos/genética , Hospitais de Ensino , Humanos , Testes de Sensibilidade Microbiana , Proteínas de Ligação às Penicilinas/genética , Reação em Cadeia da Polimerase , Staphylococcus/química , Staphylococcus/genéticaRESUMO
Bacterial biofilms play an important role in urinary tract infections (UTIs), being responsible for persistent infections that lead to recurrences and relapses. Staphylococcus saprophyticus is one of the main etiological agents of UTIs, however, little is known about biofilm production in this species and especially about its response to the antimicrobial agents used to treat UTIs when a biofilm is present. For this reason, the aim of this work was to evaluate the response of S. saprophyticus biofilms to five antimicrobial agents. Staphylococcus saprophyticus was evaluated for antimicrobial susceptibility in its planktonic form by means of minimum inhibitory concentration (MIC) and in biofilms by means of minimum inhibitory concentration in biofilm (MICB) against the following antimicrobial agents by the microdilution technique: vancomycin, oxacillin, trimethoprim/sulfamethoxazole, ciprofloxacin, and norfloxacin. Of the 169 S. saprophyticus studied, 119 produced a biofilm as demonstrated by the polystyrene plate adherence method. Biofilm cells of S. saprophyticus exhibited a considerable increase in MICB when compared to the planktonic forms, with an increase of more than 32 times in the MICB of some drugs. Some isolates switched from the category of susceptible in the planktonic condition to resistant in the biofilm state. Statistical analysis of the results showed a significant increase in MICB (p < 0.0001) for all five drugs tested in the biofilm state compared to the planktonic form. Regarding determination of the minimum bactericidal concentration in biofilm (MBCB), there were isolates for which the minimum bactericidal concentration of all drugs was equal to or higher than the highest concentration tested.
RESUMO
OBJECTIVE: To evaluate the molecular epidemiology and to georeference Staphylococcus aureus isolated from wounds and nares of patients seen at Basic Health Units (BHUs) of a Brazilian city. METHODS: Observational, cross-sectional study conducted from 2010 to 2013. A total of 119 S. aureus strains isolated from the wounds and nares of 88 patients were studied. The isolates were characterised by identifying virulence genes encoding enterotoxins A-E, haemolysins α, ß and δ, exfoliatins A, B and D, biofilm production, Panton-Valentine Leukocidin and toxic shock syndrome toxin 1, and by pulsed-field gel electrophoresis (PFGE), multilocus sequence and spa typing. RESULTS: Eighteen methicillin-resistant Staphylococcus aureus (MRSA) (6 SCCmec type II and 12 SCCmec type IV) and 101 (85%) MSSA were identified. PFGE typing resulted in the formation of eight clusters, with STs 1, 5, 8, 30, 188, 1176 and 1635 and spa type t002 being the predominant types among MSSA. The 18 MRSA belonged to STs 5, 8 and 1176 and spa types t002 and t062. CONCLUSION: The results demonstrate widespread dissemination of MSSA and MRSA clones carrying haemolysin, biofilm and toxin genes. Kernel density estimation revealed the highest density of S. aureus in the 4, 5 and 8 BHUs.
OBJECTIF: Evaluer l'épidémiologie moléculaire et géoréférencer le Staphylococcus aureus isolé de plaies et de narines de patients vus dans les unités sanitaires de base (BHU) d'une ville brésilienne. MÉTHODES: Etude observationnelle transversale réalisée de 2010 à 2013. Au total, 119 souches de S. aureus isolées de plaies et de narines de 88 patients ont été étudiées. Les isolats ont été caractérisés par l'identification de gènes de virulence codant pour les entérotoxines AE, les hémolysines α, ß et δ, les exfoliatines A, B et D, la production de biofilm, la leucocidine de Panton-Valentine et la toxine 1 du syndrome de choc toxique, et par typage par électrophorèse sur gel en champ pulsé (PFGE), séquence multilocus et spa. RÉSULTATS: Dix-huit SARM (6 de type II SCCmec et 12 de type IV SCCmec) et 101 (85%) SASM ont été identifiés. Le typage PFGE a résulté à l'obtention de huit grappes, dont STs 1, 5, 8, 30, 188, 1176 et 1635 et le type spa t002 étant les types prédominants parmi les SASM. Les 18 SARM appartenaient aux STs 5, 8 et 1176 et aux types de spa t002 et t062. CONCLUSION: Les résultats démontrent une dissémination étendue des clones de SASM et de SARM portant les gènes de l'hémolysine, de biofilm et de toxine. L'estimation de la densité par noyau a révélé la densité la plus élevée de S. aureus dans les 4, 5 et 8 BHU.
Assuntos
Staphylococcus aureus Resistente à Meticilina/genética , Infecções Estafilocócicas/epidemiologia , Ferimentos e Lesões/microbiologia , Idoso , Brasil/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Infecções Estafilocócicas/microbiologiaRESUMO
BACKGROUND: Methicillin-resistant Staphylococcus aureus poses a threat to elderly living in nursing homes. Studies focusing on the epidemiology of colonization may help in the design of infection control strategies. OBJECTIVE: To identify factors associated with MRSA colonization and the dissemination of clones among nursing home residents. METHODS: Nasal swabs were collected from 300 persons from nine nursing homes in the city of Bauru, Brazil. Resistance to methicillin was identified through amplification of the mecA gene. Strain typing (Pulsed-Field Gel Electrophoresis) and characterization of the Staphylococcal Chromosome Cassette (SCC) mec was performed. Univariate and multivariable models were used to identify predictors of overall S. aureus and MRSA carriage. RESULTS: Rates of S. aureus and MRSA colonization were 17.7 and 3.7%, respectively. Age and recent admission to a hospital were independently associated with colonization with S. aureus. MRSA colonization was associated with living in small (< 15 residents) and medium-sized (15-49 residents) facilities, as well as with recent hospitalization. Most MRSA strains carried SCCmec types II or IV, and there was evidence of clonal spread within and among different facilities. CONCLUSIONS: MRSA may be introduced in nursing homes form hospitals or arise from the community setting. Screening for asymptomatic colonization may identify persons with greater risk for infection, and is advised for residents discharged from acute care hospitals.
Assuntos
Genes Bacterianos/genética , Resistência a Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Epidemiologia Molecular , Doenças Nasais/microbiologia , Casas de Saúde , Infecções Estafilocócicas/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Brasil/epidemiologia , Estudos Transversais , DNA Bacteriano/genética , Hospitalização , Humanos , Meticilina , Resistência a Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Análise Multivariada , Proteínas de Ligação às Penicilinas/genética , Prevalência , Fatores de Risco , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacosRESUMO
INTRODUCTION: Staphylococcus spp. - both S. aureus, including methicillin-resistant strains (MRSA) and coagulase negative staphylococci (CoNS) - are relevant agents of healthcare-associated infections. Therefore, the rapid recognition of MRSA and methicillin-resistant CoNS from blood stream infections is critically important for patient management. It is worth noting that inappropriate empiric therapy has been associated with higher in-hospital mortality. MATERIAL AND METHODS: In this study we evaluated a multiplex polymerase chain reaction (multiplex PCR) standardized to detect Staphylococcus spp., S. aureus, and mecA gene-encoded oxacillin resistance directly from blood culture bottles. A total of 371 blood cultures with Gram-positive microorganisms confirmed by Gram-stain were analyzed. Results from multiplex PCR were compared to phenotypic characterization of isolates. RESULTS: Staphylococcus aureus was detected in 85 (23.0%) blood cultures and CoNS in 286 (77.0%). There was 100% agreement between phenotypic and multiplex PCR identification. Forty-three (50.6%) of the 85 S. aureus carried the mecA gene and among the 286 CoNS, 225 (78.7%) were positive for the mecA gene. CONCLUSIONS: The multiplex PCR assay developed here was found to be sensitive, specific, rapid, and showed good agreement with the phenotypic results besides being less expensive. This PCR method could be used in clinical laboratories for rapid identification and initiation of specific and effective treatment, reducing patient mortality and morbidity. Furthermore, this method may reduce misuse of antimicrobial classes that are more expensive and toxic, thus contributing to the selection of antibiotic-resistant Staphylococcus spp.
Assuntos
Bacteriemia/diagnóstico , Proteínas de Bactérias/genética , Sangue/microbiologia , Staphylococcus aureus Resistente à Meticilina/genética , Reação em Cadeia da Polimerase Multiplex , Proteínas de Ligação às Penicilinas/genética , Infecções Estafilocócicas/diagnóstico , Antibacterianos/farmacologia , Bacteriemia/microbiologia , Proteínas de Bactérias/isolamento & purificação , Hemocultura , DNA Bacteriano/genética , Humanos , Oxacilina/farmacologia , Proteínas de Ligação às Penicilinas/isolamento & purificação , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificaçãoRESUMO
ABSTRACT Introduction: Staphylococcus spp. - both S. aureus, including methicillin-resistant strains (MRSA) and coagulase negative staphylococci (CoNS) - are relevant agents of healthcare-associated infections. Therefore, the rapid recognition of MRSA and methicillin-resistant CoNS from blood stream infections is critically important for patient management. It is worth noting that inappropriate empiric therapy has been associated with higher in-hospital mortality. Material and methods: In this study we evaluated a multiplex polymerase chain reaction (multiplex PCR) standardized to detect Staphylococcus spp., S. aureus, and mecA gene-encoded oxacillin resistance directly from blood culture bottles. A total of 371 blood cultures with Gram-positive microorganisms confirmed by Gram-stain were analyzed. Results from multiplex PCR were compared to phenotypic characterization of isolates. Results: Staphylococcus aureus was detected in 85 (23.0%) blood cultures and CoNS in 286 (77.0%). There was 100% agreement between phenotypic and multiplex PCR identification. Forty-three (50.6%) of the 85 S. aureus carried the mecA gene and among the 286 CoNS, 225 (78.7%) were positive for the mecA gene. Conclusions: The multiplex PCR assay developed here was found to be sensitive, specific, rapid, and showed good agreement with the phenotypic results besides being less expensive. This PCR method could be used in clinical laboratories for rapid identification and initiation of specific and effective treatment, reducing patient mortality and morbidity. Furthermore, this method may reduce misuse of antimicrobial classes that are more expensive and toxic, thus contributing to the selection of antibiotic-resistant Staphylococcus spp.
Assuntos
Humanos , Proteínas de Bactérias/genética , Sangue/microbiologia , Bacteriemia/diagnóstico , Proteínas de Ligação às Penicilinas/genética , Staphylococcus aureus Resistente à Meticilina/genética , Reação em Cadeia da Polimerase Multiplex , Oxacilina/farmacologia , Infecções Estafilocócicas/diagnóstico , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/efeitos dos fármacos , Proteínas de Bactérias/isolamento & purificação , DNA Bacteriano/genética , Bacteriemia/microbiologia , Proteínas de Ligação às Penicilinas/isolamento & purificação , Hemocultura , Antibacterianos/farmacologiaRESUMO
Abstract INTRODUCTION: Wounds can be colonized by methicillin-resistant Staphylococcus aureus (MRSA). METHODS: We evaluated the prevalence of S. aureus and MRSA in the wounds of patients treated at Basic Health Units in Brazil and identified risk factors associated with their presence. RESULTS: The prevalence rates of S. aureus and MRSA were 51.5% and 8.7%, respectively. There was a correlation between the presence of S. aureus in wounds and nostrils (p<0.01). A positive association was detected between S. aureus infection and previous benzylpenicillin use (p=0.02). No associations were observed for MRSA. CONCLUSIONS: Multidrug-resistant pathogens are present in primary healthcare settings in Brazil.
Assuntos
Humanos , Masculino , Feminino , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/isolamento & purificação , Ferimentos e Lesões/microbiologia , Atenção Primária à Saúde , Fatores Socioeconômicos , Infecções Estafilocócicas/diagnóstico , Brasil/epidemiologia , Doença Crônica , Prevalência , Estudos Transversais , Fatores de Risco , Staphylococcus aureus Resistente à Meticilina/isolamento & purificaçãoRESUMO
Abstract Staphylococcus aureus and Staphylococcus saprophyticus are the most common and most important staphylococcal species associated with urinary tract infections. The objective of the present study was to compare and to evaluate the accuracy of four phenotypic methods for the detection of beta-lactamase production in Staphylococcus spp. Seventy-three strains produced a halo with a diameter ≤28 mm (penicillin resistant) and all of them were positive for the blaZ gene. Among the 28 susceptible strain (halo ≥29 mm), 23 carried the blaZ gene and five did not. The zone edge test was the most sensitive (90.3%), followed by MIC determination (85.5%), but the specificity of the former was low (40.0%). The nitrocefin test was the least sensitive (28.9%). However, the nitrocefin test together with the disk diffusion method showed the highest specificity (100%). The present results demonstrated that the zone edge test was the most sensitive phenotypic test for detection of beta-lactamase, although it is still not an ideal test to detect this type of resistance since its specificity was low. However, the inhibition halo diameter of the penicillin disk can be used together with the zone edge test since the same disk is employed in the two tests. Combined analysis of the two tests shows a sensitivity of 90.3% and specificity of 100%, proving better sensitivity, especially for S. saprophyticus. This is a low-cost test of easy application and interpretation that can be used in small and medium-sized laboratories where susceptibility testing is usually performed by the disk diffusion method.
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beta-Lactamases/genética , beta-Lactamases/metabolismo , Testes de Sensibilidade Microbiana , Resistência beta-Lactâmica , Infecções Estafilocócicas/microbiologia , Infecções Urinárias/microbiologia , Resistência às Penicilinas , Sensibilidade e Especificidade , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Staphylococcus saprophyticus/efeitos dos fármacos , Staphylococcus saprophyticus/genética , Staphylococcus saprophyticus/metabolismo , GenótipoRESUMO
Staphylococcus aureus and Staphylococcus saprophyticus are the most common and most important staphylococcal species associated with urinary tract infections. The objective of the present study was to compare and to evaluate the accuracy of four phenotypic methods for the detection of beta-lactamase production in Staphylococcus spp. Seventy-three strains produced a halo with a diameter ≤ 28 mm (penicillin resistant) and all of them were positive for the blaZ gene. Among the 28 susceptible strain (halo ≥ 29 mm), 23 carried the blaZ gene and five did not. The zone edge test was the most sensitive (90.3%), followed by MIC determination (85.5%), but the specificity of the former was low (40.0%). The nitrocefin test was the least sensitive (28.9%). However, the nitrocefin test together with the disk diffusion method showed the highest specificity (100%). The present results demonstrated that the zone edge test was the most sensitive phenotypic test for detection of beta-lactamase, although it is still not an ideal test to detect this type of resistance since its specificity was low. However, the inhibition halo diameter of the penicillin disk can be used together with the zone edge test since the same disk is employed in the two tests. Combined analysis of the two tests shows a sensitivity of 90.3% and specificity of 100%, proving better sensitivity, especially for S. saprophyticus. This is a low-cost test of easy application and interpretation that can be used in small and medium-sized laboratories where susceptibility testing is usually performed by the disk diffusion method.(AU)
Assuntos
Staphylococcus , Sistema Urinário/patologia , beta-Lactamases/genética , FenótipoRESUMO
Staphylococcus aureus and Staphylococcus saprophyticus are the most common and most important staphylococcal species associated with urinary tract infections. The objective of the present study was to compare and to evaluate the accuracy of four phenotypic methods for the detection of beta-lactamase production in Staphylococcus spp. Seventy-three strains produced a halo with a diameter ≤28mm (penicillin resistant) and all of them were positive for the blaZ gene. Among the 28 susceptible strain (halo ≥29mm), 23 carried the blaZ gene and five did not. The zone edge test was the most sensitive (90.3%), followed by MIC determination (85.5%), but the specificity of the former was low (40.0%). The nitrocefin test was the least sensitive (28.9%). However, the nitrocefin test together with the disk diffusion method showed the highest specificity (100%). The present results demonstrated that the zone edge test was the most sensitive phenotypic test for detection of beta-lactamase, although it is still not an ideal test to detect this type of resistance since its specificity was low. However, the inhibition halo diameter of the penicillin disk can be used together with the zone edge test since the same disk is employed in the two tests. Combined analysis of the two tests shows a sensitivity of 90.3% and specificity of 100%, proving better sensitivity, especially for S. saprophyticus. This is a low-cost test of easy application and interpretation that can be used in small and medium-sized laboratories where susceptibility testing is usually performed by the disk diffusion method.
Assuntos
Testes de Sensibilidade Microbiana , Resistência beta-Lactâmica , beta-Lactamases/genética , beta-Lactamases/metabolismo , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Genótipo , Resistência às Penicilinas , Sensibilidade e Especificidade , Infecções Estafilocócicas/microbiologia , Staphylococcus saprophyticus/efeitos dos fármacos , Staphylococcus saprophyticus/genética , Staphylococcus saprophyticus/metabolismo , Infecções Urinárias/microbiologiaRESUMO
INTRODUCTION: Wounds can be colonized by methicillin-resistant Staphylococcus aureus (MRSA). METHODS: We evaluated the prevalence of S. aureus and MRSA in the wounds of patients treated at Basic Health Units in Brazil and identified risk factors associated with their presence. RESULTS: The prevalence rates of S. aureus and MRSA were 51.5% and 8.7%, respectively. There was a correlation between the presence of S. aureus in wounds and nostrils (p<0.01). A positive association was detected between S. aureus infection and previous benzylpenicillin use (p=0.02). No associations were observed for MRSA. CONCLUSIONS: Multidrug-resistant pathogens are present in primary healthcare settings in Brazil.
Assuntos
Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/isolamento & purificação , Ferimentos e Lesões/microbiologia , Brasil/epidemiologia , Doença Crônica , Estudos Transversais , Feminino , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Prevalência , Atenção Primária à Saúde , Fatores de Risco , Fatores Socioeconômicos , Infecções Estafilocócicas/diagnósticoRESUMO
The multidrug resistant and the emergence of methicillin-resistant staphylococci isolated from animals, food, and humans are public health concern. These microorganisms produce different toxins related to food poisoning in humans. This study aimed to characterize Staphylococcus spp. isolated from two organic milk farms in Brazil. A total of 259 milk samples were collected, from which 58 (22.4%) Staphylococcus spp. were isolated. The highest sensibility to ceftiofur and sulfamethoxazole/trimethoprim was observed in 96.6% of Staphylococcus spp., and whereas 89% were resistant to penicillin G. The mecA gene was detected in 13.8% of the isolates. SEA and SEC were the most common enterotoxins detected. PFGE revealed genetic heterogeneity from S. intermedius and S. warneri analyzed, while S. aureus presented similar profiles among isolates from the two studied herds. To the best of our knowledge, the current study describes for the first time presence of enterotoxins, mecA gene, and genetic diversity of staphylococci isolated from organic dairy farms in Brazil.(AU)
A emergência de estafilococos multirresistentes e resistentes à meticilina, isolados de animais, alimentos e humanos é uma preocupação em saúde pública. Esses micro-organismos produzem diferentes toxinas relacionadas à intoxicação alimentar em humanos. Este estudo caracterizou Staphylococcus spp. isolados em duas fazendas orgânicas no Brasil. Foram coletadas 259 amostras de leite em duas propriedades leiteiras orgânicas, nas quais 58 (22,4%) estirpes de Staphylococcus spp. foram isoladas. A maior sensibilidade dos isolados foi observada para ceftiofur e sulfametoxazol/trimetoprim em 96,6%. Em contraste, acima de 89% de resistência dos estafilicocos foi encontrada para penicilina G. O gene mecA foi identificado em 13,8% dos isolados. SEA e SEC foram as enterotoxinas mais comumente detectadas. PFGE revelou heterogeneidade genética entre S. intermedius e S. warneri, enquanto S. aureus demonstraram perfis semelhantes entre isolados dos dois rebanhos estudados. Relata-se pela primeira vez no Brasil a detecção de enterotoxinas, o gene mecA e diversidade genética em estafilococos isolados de vacas em produção orgânica.(AU)
Assuntos
Animais , Bovinos , Farmacorresistência Viral Múltipla , Alimentos Orgânicos , Genes MDR , Leite/microbiologia , Staphylococcus/isolamento & purificação , Eletroforese em Gel de Campo Pulsado , Enterotoxinas/genética , Variação GenéticaRESUMO
The multidrug resistant and the emergence of methicillin-resistant staphylococci isolated from animals, food, and humans are public health concern. These microorganisms produce different toxins related to food poisoning in humans. This study aimed to characterize Staphylococcus spp. isolated from two organic milk farms in Brazil. A total of 259 milk samples were collected, from which 58 (22.4%) Staphylococcus spp. were isolated. The highest sensibility to ceftiofur and sulfamethoxazole/trimethoprim was observed in 96.6% of Staphylococcus spp., and whereas 89% were resistant to penicillin G. The mecA gene was detected in 13.8% of the isolates. SEA and SEC were the most common enterotoxins detected. PFGE revealed genetic heterogeneity from S. intermedius and S. warneri analyzed, while S. aureus presented similar profiles among isolates from the two studied herds. To the best of our knowledge, the current study describes for the first time presence of enterotoxins, mecA gene, and genetic diversity of staphylococci isolated from organic dairy farms in Brazil.(AU)
A emergência de estafilococos multirresistentes e resistentes à meticilina, isolados de animais, alimentos e humanos é uma preocupação em saúde pública. Esses micro-organismos produzem diferentes toxinas relacionadas à intoxicação alimentar em humanos. Este estudo caracterizou Staphylococcus spp. isolados em duas fazendas orgânicas no Brasil. Foram coletadas 259 amostras de leite em duas propriedades leiteiras orgânicas, nas quais 58 (22,4%) estirpes de Staphylococcus spp. foram isoladas. A maior sensibilidade dos isolados foi observada para ceftiofur e sulfametoxazol/trimetoprim em 96,6%. Em contraste, acima de 89% de resistência dos estafilicocos foi encontrada para penicilina G. O gene mecA foi identificado em 13,8% dos isolados. SEA e SEC foram as enterotoxinas mais comumente detectadas. PFGE revelou heterogeneidade genética entre S. intermedius e S. warneri, enquanto S. aureus demonstraram perfis semelhantes entre isolados dos dois rebanhos estudados. Relata-se pela primeira vez no Brasil a detecção de enterotoxinas, o gene mecA e diversidade genética em estafilococos isolados de vacas em produção orgânica.(AU)