RESUMO
This study aims to determine the prevalence of Staphylococcus aureus colonizing patients and ICU environment of a teaching hospital, the virulence and antimicrobial susceptibility profile of the isolates, and to evaluate the genetic relationship among them. A total of 536 swabs (134 of patients and 402 of ICU environment) were collected and analyzed to detect S. aureus. The antimicrobial susceptibility of the isolates was determined by disk diffusion test, and the detection of the mecA and virulence factors genes was performed by PCR, in addition to SCCmec typing. The genetic similarity of the isolates was determined by PFGE. Staphylococcus aureus was isolated in 12.7% of the swabs. The prevalence of colonization was 13.4% in patients and 12.4% in the environmental samples. The multidrug resistance was determined in 82.4% of the isolates. The prevalence of methicillin-resistant S. aureus was 20.6%, with 50.0% classified as SCCmec IV. The intermediate resistance to vancomycin was detected in 5.9% and 4.4% of the isolates obtained from patients and environment, respectively. Identical isolates obtained from different patients and sources were grouped into several clusters. The results showed dissemination of multidrug-resistant strains between patients and fomites and the persistence of MRSA and VISA isolates in the ICU environment.
Assuntos
Antibacterianos/farmacologia , Resistência a Meticilina , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Staphylococcus aureus/patogenicidade , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana , Feminino , Variação Genética , Humanos , Unidades de Terapia Intensiva/estatística & dados numéricos , Masculino , Meticilina/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Filogenia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Vancomicina/farmacologia , Virulência , Fatores de Virulência/genéticaRESUMO
INTRODUCTION: Bacterial tonsillitis is an upper respiratory tract infection that occurs primarily in children and adolescents. Staphylococcus aureus is one of the most frequent pathogens in the etiology of tonsillitis and its relevance is due to its antimicrobial resistance and persistence in the internal tissues of the tonsils. Tonsillectomy is indicated in cases of recurrent tonsillitis after several failures of antibiotic therapy. MATERIAL AND METHODS: In this study we evaluated 123 surgically removed tonsils from patients who had history of recurrent tonsillitis. The tonsils were submitted to microbiological analysis for detection of S. aureus. The isolates were identified by PCR for femA gene. Antimicrobial susceptibility of the isolates was determined by disk diffusion tests. All isolates were submitted to PCR to detect mecA and Panton-Valentine leucocidin (PVL) genes. The genetic similarity among all isolates was determined by pulsed field gel electrophoresis. RESULTS: Sixty-one S. aureus isolates were obtained from 50 patients (40.7%) with mean age of 11.7 years. The isolates showed high level resistance to penicillin (83.6%), 9.8% had inducible MLSb phenotype, and 18.0% were considered multidrug resistant (MDR). mecA gene was detected in two isolates and the gene coding for PVL was identified in one isolate. The genetic similarity analysis showed high diversity among the isolates. More than one genetically different isolate was identified from the same patient, and identical isolates were obtained from different patients. CONCLUSIONS: MDR isolates colonizing tonsils even without infection, demonstrate persistence of the bacterium and possibility of antimicrobial resistance dissemination and recurrence of infection. A specific clone in patients colonized by S. aureus was not demonstrated.
Assuntos
Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Tonsilite/microbiologia , Adolescente , Adulto , Antibacterianos/farmacologia , Criança , Pré-Escolar , Estudos Transversais , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Eletroforese em Gel de Campo Pulsado , Feminino , Humanos , Lactente , Masculino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Staphylococcus aureus/efeitos dos fármacos , Tonsilectomia/métodos , Tonsilite/cirurgia , Adulto JovemRESUMO
ABSTRACT Introduction: Bacterial tonsillitis is an upper respiratory tract infection that occurs primarily in children and adolescents. Staphylococcus aureus is one of the most frequent pathogens in the etiology of tonsillitis and its relevance is due to its antimicrobial resistance and persistence in the internal tissues of the tonsils. Tonsillectomy is indicated in cases of recurrent tonsillitis after several failures of antibiotic therapy. Material and methods: In this study we evaluated 123 surgically removed tonsils from patients who had history of recurrent tonsillitis. The tonsils were submitted to microbiological analysis for detection of S. aureus. The isolates were identified by PCR for femA gene. Antimicrobial susceptibility of the isolates was determined by disk diffusion tests. All isolates were submitted to PCR to detect mecA and Panton-Valentine leucocidin (PVL) genes. The genetic similarity among all isolates was determined by pulsed field gel electrophoresis. Results: Sixty-one S. aureus isolates were obtained from 50 patients (40.7%) with mean age of 11.7 years. The isolates showed high level resistance to penicillin (83.6%), 9.8% had inducible MLSb phenotype, and 18.0% were considered multidrug resistant (MDR). mecA gene was detected in two isolates and the gene coding for PVL was identified in one isolate. The genetic similarity analysis showed high diversity among the isolates. More than one genetically different isolate was identified from the same patient, and identical isolates were obtained from different patients. Conclusions: MDR isolates colonizing tonsils even without infection, demonstrate persistence of the bacterium and possibility of antimicrobial resistance dissemination and recurrence of infection. A specific clone in patients colonized by S. aureus was not demonstrated.
Assuntos
Humanos , Masculino , Feminino , Lactente , Pré-Escolar , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Adulto Jovem , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação , Staphylococcus aureus/genética , Tonsilite/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Tonsilectomia/métodos , Tonsilite/cirurgia , Reação em Cadeia da Polimerase , Estudos Transversais , Eletroforese em Gel de Campo Pulsado , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Antibacterianos/farmacologiaRESUMO
BACKGROUND: 10-valent conjugate pneumococcal vaccine/PCV10 was introduced in the Brazilian National Immunization Program along the year of 2010. We assessed the direct effectiveness of PCV10 vaccination in preventing nasopharyngeal/NP pneumococcal carriage in infants. METHODS: A cross-sectional population-based household survey was conducted in Goiania Brazil, from December/2010-February/2011 targeting children aged 7-11 m and 15-18 m. Participants were selected using a systematic sampling. NP swabs, demographic data, and vaccination status were collected from 1,287 children during home visits. Main outcome and exposure of interest were PCV10 vaccine-type carriage and dosing schedules (3p+0, 2p+0, and one catch-up dose), respectively. Pneumococcal carriage was defined by a positive culture and serotyping was performed by Quellung reaction. Rate ratio/RR was calculated as the ratio between the prevalence of vaccine-types carriage in children exposed to different schedules and unvaccinated for PCV10. Adjusted RR was estimated using Poisson regression. PCV10 effectiveness/VE on vaccine-type carriage was calculated as 1-RR*100. RESULTS: The prevalence of pneumococcal carriage was 41.0% (95%CI: 38.4-43.7). Serotypes covered by PCV10 and PCV13 were 35.2% and 53.0%, respectively. Vaccine serotypes 6B (11.6%), 23F (7.8%), 14 (6.8%), and 19F (6.6%) were the most frequently observed. After adjusted for confounders, children who had received 2p+0 or 3p+0 dosing schedule presented a significant reduction in pneumococcal vaccine-type carriage, with PCV10 VE equal to 35.9% (95%CI: 4.2-57.1; p = 0.030) and 44.0% (95%CI: 14.-63.5; p = 0.008), respectively, when compared with unvaccinated children. For children who received one catch-up dose, no significant VE was detected (p = 0.905). CONCLUSION: PCV10 was associated with high protection against vaccine-type carriage with 2p+0 and 3p+0 doses for children vaccinated before the second semester of life. The continuous evaluation of carriage serotypes distribution is likely to be useful for evaluating the long-term effectiveness and impact of pneumococcal vaccination on serotypes reduction.
Assuntos
Portador Sadio/imunologia , Portador Sadio/microbiologia , Infecções Pneumocócicas/imunologia , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas/imunologia , Vacinação , Distribuição por Idade , Brasil , Criança , Relação Dose-Resposta Imunológica , Humanos , Lactente , Nasofaringe/imunologia , Nasofaringe/microbiologia , Infecções Pneumocócicas/microbiologiaRESUMO
Background: In Latin America, few studies have been carried out on methicillin-resistant Staphylococcus aureus carriage in the pediatric population. We conducted a survey of nasal S. aureus carriage in neonates and in children attending the pediatric outpatient clinics in a large Brazilian city with high antimicrobial consumption. Methods: Pernasal swabs of neonates were collected upon admission and at discharge in four neonatal intensive care units and of children less than five years of age during outpatient visits. Methicillin-resistant S. aureus isolates were characterized for antibiotic susceptibility, mec gene presence, pulsed-field gel electrophoresis, spa type, SCCmec-type, multilocus sequence type, and presence of Panton-Valentine leukocidin genes. Results: S. aureus was carried by 9.1% and 20.1% of the 701 neonates and of 2034 children attending the outpatient clinics, respectively; methicillin-resistant S. aureus carriage was detected in 0.6% and 0.2%, of the these populations, respectively. Healthcare-associated methicillin-resistant S. aureus strains found in neonates from neonatal intensive care units and outpatients were genetically related to the Brazilian (SCCmec-III, ST239) and to the Pediatric (SCCmec-IV, ST5) clones. Community-associated methicillin-resistant S. aureus was only detected in outpatients. None of the methicillin-resistant S. aureus strains contained the Panton-Valentine leukocidin gene. Methicillin-resistant S. aureus strains related to the Brazilian clone showed multidrug resistance pattern. Conclusions: Despite the high antibiotic pressure in our area, and the cross transmission of the healthcare-associated methicillin-resistant S. aureus clones between neonatal intensive care units and outpatients, the prevalence of methicillin-resistant S. aureus carriage is still low in our setting. .
Assuntos
Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Portador Sadio/microbiologia , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Cavidade Nasal/microbiologia , Infecções Estafilocócicas/epidemiologia , Instituições de Assistência Ambulatorial , Antibacterianos/farmacologia , Brasil/epidemiologia , Eletroforese em Gel de Campo Pulsado , Testes de Sensibilidade Microbiana , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Infecções Estafilocócicas/microbiologiaRESUMO
BACKGROUND: In Latin America, few studies have been carried out on methicillin-resistant Staphylococcus aureus carriage in the pediatric population. We conducted a survey of nasal S. aureus carriage in neonates and in children attending the pediatric outpatient clinics in a large Brazilian city with high antimicrobial consumption. METHODS: Pernasal swabs of neonates were collected upon admission and at discharge in four neonatal intensive care units and of children less than five years of age during outpatient visits. Methicillin-resistant S. aureus isolates were characterized for antibiotic susceptibility, mec gene presence, pulsed-field gel electrophoresis, spa type, SCCmec-type, multilocus sequence type, and presence of Panton-Valentine leukocidin genes. RESULTS: S. aureus was carried by 9.1% and 20.1% of the 701 neonates and of 2034 children attending the outpatient clinics, respectively; methicillin-resistant S. aureus carriage was detected in 0.6% and 0.2%, of the these populations, respectively. Healthcare-associated methicillin-resistant S. aureus strains found in neonates from neonatal intensive care units and outpatients were genetically related to the Brazilian (SCCmec-III, ST239) and to the Pediatric (SCCmec-IV, ST5) clones. Community-associated methicillin-resistant S. aureus was only detected in outpatients. None of the methicillin-resistant S. aureus strains contained the Panton-Valentine leukocidin gene. Methicillin-resistant S. aureus strains related to the Brazilian clone showed multidrug resistance pattern. CONCLUSIONS: Despite the high antibiotic pressure in our area, and the cross transmission of the healthcare-associated methicillin-resistant S. aureus clones between neonatal intensive care units and outpatients, the prevalence of methicillin-resistant S. aureus carriage is still low in our setting.
Assuntos
Portador Sadio/microbiologia , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Cavidade Nasal/microbiologia , Infecções Estafilocócicas/epidemiologia , Instituições de Assistência Ambulatorial , Antibacterianos/farmacologia , Brasil/epidemiologia , Criança , Pré-Escolar , Eletroforese em Gel de Campo Pulsado , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/microbiologiaRESUMO
BACKGROUND: Nasal colonization with coagulase-negative Staphylococcus (CoNS) has been described as a risk factor for subsequent systemic infection. In this study, we evaluated the genetic profile of CoNS isolates colonizing the nares of children admitted to a neonatal intensive care unit (NICU). METHODS: We assessed CoNS carriage at admittance and discharge among newborns admitted to a NICU from July 2007 through May 2008 in one of the major municipalities of Brazil. Isolates were screened on mannitol salt agar and tryptic soy broth and tested for susceptibility to antimicrobials using the disc diffusion method. Polymerase chain reaction (PCR) was used to determine the species, the presence of the mecA gene, and to perform SCCmec typing. S. epidermidis and S. haemolyticus isolated from the same child at both admission and discharge were characterized by PFGE. RESULTS: Among 429 neonates admitted to the NICU, 392 (91.4%) had nasal swabs collected at both admission and discharge. The incidence of CoNS during the hospitalization period was 55.9% (95% confidence interval [CI]: 50.9-60.7). The most frequently isolated species were S. haemolyticus (38.3%) and S.epidermidis (38.0%). Multidrug resistance (MDR) was detected in 2.2% and 29.9% of the CoNS isolates, respectively at admittance and discharge (p = 0.053). The mecA gene was more prevalent among strains isolated at discharge (83.6%) than those isolated at admission (60%); overall, SCCmec type I was isolated most frequently. The length of hospitalization was associated with colonization by MDR isolates (p < 0.005). Great genetic diversity was observed among S. epidermidis and S. haemolyticus. CONCLUSIONS: NICU represents an environment of risk for colonization by MDR CoNS. Neonates admitted to the NICU can become a reservoir of CoNS strains with the potential to spread MDR strains into the community.
Assuntos
Unidades de Terapia Intensiva , Infecções Estafilocócicas/epidemiologia , Staphylococcus/genética , Staphylococcus/isolamento & purificação , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Técnicas de Tipagem Bacteriana , Brasil/epidemiologia , Coagulase/genética , Coagulase/metabolismo , Farmacorresistência Bacteriana , Feminino , Hospitalização , Humanos , Recém-Nascido , Unidades de Terapia Intensiva/estatística & dados numéricos , Masculino , Testes de Sensibilidade Microbiana , Epidemiologia Molecular , Infecções Estafilocócicas/microbiologia , Staphylococcus/classificação , Staphylococcus/enzimologiaRESUMO
Listeria monocytogenes, a foodborne pathogen causes listeriosis, a fatal disease in about 30% of cases that affects mainly immunocompromised persons. The aim of this research was to characterize L. monocytogenes pulsed-field gel electrophoresis (PFGE) types isolated from meat products collected at public markets in Araguaina city, TO. Sixty samples of raw ground beef and frescal sausage were analyzed during the second half of 2008. Five out of 30 samples (16.7%) of raw ground beef tested positive for L. monocytogenes, three of which were classified as serotype 1/2b and two as serotype 4b. Among the 30 samples of sausage collected, two strains of L. monocytogenes were isolated (6.7%), one of them belonging to serotype 1/2a and the other belonging to serotype 1/2b. The restriction enzymes used were ApaI and SmaI. Similarities among the strains were determined by Dice coefficient. The macro restriction profile obtained by using SmaI enzyme allowed the distribution of seven strains in two clusters, two pulsotypes and two subtypes. The result indicates that L. monocytogenes isolates, belonging to serotype 4b, 1/2a and 1/2b, are strongly correlated within the same serotype group, and in some cases among different serotypes, suggesting that they have a common source.
Listeria monocytogenes é um patógeno de origem alimentar que causa a listeriose, doença fatal em aproximadamente 30% dos casos, e que afeta principalmente pessoas imunocomprometidas. O presente trabalho teve como objetivo analisar os perfis PFGE de cepas de L. monocytogenes isoladas de produtos de origem animal, obtidos em mercados públicos da cidade de Araguaína, TO. Foram analisadas 60 amostras de carne moída crua e de linguiça frescal, no segundo semestre de 2008. Cinco (16,7%) das 30 amostras de carne moída crua foram positivas ao patógeno, sendo que três pertenciam ao sorotipo 1/2b e duas ao sorotipo 4b. Das 30 amostras de linguiça mista frescal, duas (6,7%) foram positivas para L. monocytogenes, sendo uma do sorotipo 1/2a e outra do 1/2b. Foram utilizadas as enzimas de restrição ApaI e SmaI. A similaridade entre eles foi determinada pelo coeficiente de Dice. A análise do perfil de macrorestrição com a enzima SmaI permitiu a distribuição dos sete isolados em dois clusters, dois pulsotipos e dois subtipos. Os resultados permitiram concluir que os isolados de L. monocytogenes sorotipos 4b, 1/2a e 1/2b foram fortemente correlacionados dentro dos mesmos sorotipos e em alguns casos entre diferentes sorotipos, sugerindo uma fonte comum.
RESUMO
Listeria monocytogenes, a foodborne pathogen causes listeriosis, a fatal disease in about 30% of cases that affects mainly immunocompromised persons. The aim of this research was to characterize L. monocytogenes pulsed-field gel electrophoresis (PFGE) types isolated from meat products collected at public markets in Araguaina city, TO. Sixty samples of raw ground beef and frescal sausage were analyzed during the second half of 2008. Five out of 30 samples (16.7%) of raw ground beef tested positive for L. monocytogenes, three of which were classified as serotype 1/2b and two as serotype 4b. Among the 30 samples of sausage collected, two strains of L. monocytogenes were isolated (6.7%), one of them belonging to serotype 1/2a and the other belonging to serotype 1/2b. The restriction enzymes used were ApaI and SmaI. Similarities among the strains were determined by Dice coefficient. The macro restriction profile obtained by using SmaI enzyme allowed the distribution of seven strains in two clusters, two pulsotypes and two subtypes. The result indicates that L. monocytogenes isolates, belonging to serotype 4b, 1/2a and 1/2b, are strongly correlated within the same serotype group, and in some cases among different serotypes, suggesting that they have a common source.
Listeria monocytogenes é um patógeno de origem alimentar que causa a listeriose, doença fatal em aproximadamente 30% dos casos, e que afeta principalmente pessoas imunocomprometidas. O presente trabalho teve como objetivo analisar os perfis PFGE de cepas de L. monocytogenes isoladas de produtos de origem animal, obtidos em mercados públicos da cidade de Araguaína, TO. Foram analisadas 60 amostras de carne moída crua e de linguiça frescal, no segundo semestre de 2008. Cinco (16,7%) das 30 amostras de carne moída crua foram positivas ao patógeno, sendo que três pertenciam ao sorotipo 1/2b e duas ao sorotipo 4b. Das 30 amostras de linguiça mista frescal, duas (6,7%) foram positivas para L. monocytogenes, sendo uma do sorotipo 1/2a e outra do 1/2b. Foram utilizadas as enzimas de restrição ApaI e SmaI. A similaridade entre eles foi determinada pelo coeficiente de Dice. A análise do perfil de macrorestrição com a enzima SmaI permitiu a distribuição dos sete isolados em dois clusters, dois pulsotipos e dois subtipos. Os resultados permitiram concluir que os isolados de L. monocytogenes sorotipos 4b, 1/2a e 1/2b foram fortemente correlacionados dentro dos mesmos sorotipos e em alguns casos entre diferentes sorotipos, sugerindo uma fonte comum.
RESUMO
A child's death due to pneumococcal meningitis after contracting the disease in an after-school programme prompted an investigation to assess nasopharyngeal (NP) carriage among her contacts. The serotype of the meningitis case isolate was determined, together with the serotypes of the NP specimens of contacts, comprising the case patient's brother, the case patient's after-school programme contacts and the brother's day-care centre (DCC) contacts. NP swabs from 155 children and 69 adults were obtained. Real-time PCR and conventional multiplex PCR (CM-PCR) assays were used to detect pneumococcal carriage and determine serotypes. Broth-enriched culture of NP specimens followed by pneumococcal isolation and Quellung-based serotyping were also performed. DNA extracts prepared from cerebrospinal fluid of the index case and from the NP strain isolated from the brother and from one attendee of the brother's DCC were subjected to genotyping. Pneumococcal carriage assessed by real-time PCR and culture was 49.6 and 36.6%, respectively (P<0.05). Twenty-three serotypes were detected using CM-PCR, with serotypes 6A/6B, 14, 19F, 6C/6D, 22F/22A, 23F and 11A/11D being the most frequent. All eight serotype 22F/22A NP specimens recovered were from children attending the brother's DCC. The meningitis case isolate and the NP carriage isolate from the patient's brother were both serotype 22F and shared the same new multilocus sequence type (ST6403) with the attendee of the brother's DCC. CM-PCR proved to be useful for assessing carriage serotype distribution in a setting of high-risk pneumococcal transmission. The causal serotype appeared to be linked to the brother of the case patient and attendees of his DCC.