RESUMO
PURPOSE: Staphylococcus aureus is one of the main causative agents of hospital-acquired (HA) infections. In Mexico, information about the characteristics of clinical S. aureus isolates is limited. Our aim was to characterize S. aureus strains obtained from blood cultures of paediatric patients treated in a tertiary care hospital. MATERIALS AND METHODS: We analysed 249 S. aureus isolates over the period from 2006 to 2019, and their resistance profiles were determined. The isolates were classified into methicillin-resistant S. aureus (MRSA) or methicillin-sensitive S. aureus (MSSA). Staphylococcal cassettes chromosome mec (SCCmec) were detected. Virulence genes (cna, clfA, clfB, eta, etb, fnbA, fnbB, hla, pvl, sec, and tsst) were amplified, and their clonal relationships were established by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and clonal complex (CC) typing. We reviewed one hundred medical files to collect clinical information. RESULTS: Thirty-eight percent of the isolates were MRSA and showed an expanded profile of resistance to other non-beta-lactam antibiotics, while MSSA strains presented a reduced resistance profile. SCCmec-II was the most frequent element (86.3%). Eight virulence factors were detected in MSSA and six in MRSA. The pvl gene was detected in four MRSA-SCCmec-IV isolates (P≤0.0001). MRSA isolates were distributed among 14 clones and were classified into 15 sequence types (ST); the most frequent was ST1011 (17%). The most common CC in MRSA was CC5 (69%, P≤0.0001), and in MSSA, it was CC30 (30%, P≤0.0001). Eighty-seven percent of MRSA isolates were HA-MRSA, and 13% were community-acquired MRSA (CA-MRSA). Of 21 HA-MRSA isolates, 17 had SCCmec-II, while two CA-MRSA isolates had SCCmec-IV. Of MSSA isolates, 77% were derived from HA infections and 23% from CA infections. CONCLUSION: MSSA isolates had more virulence factors. MRSA isolates were resistant to more non-beta-lactam antibiotics, and those with SCCmec-IV expressed a greater variety of virulence factors. Most S. aureus isolates belonged to CC5.
RESUMO
OBJECTIVES: To evaluate the usefulness of real-time polymerase chain reaction (RT-PCR) as a diagnostic method for the detection of Bordetella pertussis in hospitalized patients aged <1 year with a clinical diagnosis of whooping cough, as well as to identify the role of household contacts as a source of infection. STUDY DESIGN: This was a prospective, multicenter study of infants aged <1 year who were hospitalized with symptoms suggestive of whooping cough. Nasopharyngeal samples were obtained for culture and RT-PCR testing. The clinical and epidemiologic characteristics and outcomes were analyzed. B pertussis detection and symptoms in household contacts of patients diagnosed with pertussis were studied. RESULTS: A total of 286 patients were included; of these, 67.1% had B pertussis and 4.5% had Bordetella spp. Complications occurred in 20% of patients, and the mortality rate was 6.7%. Of 434 contacts studied, 111 were mothers of study infants, representing the most frequently B pertussis-infected group and the main symptomatic contact. CONCLUSION: The use of RT-PCR permits improved detection and diagnosis of pertussis and a better understanding of the epidemiology of sources of infection. The complications and mortality rate of pertussis continue to be high. Household contacts are confirmed as a frequent source of infection of B pertussis in young children.
Assuntos
Bordetella pertussis/genética , Reação em Cadeia da Polimerase em Tempo Real , Coqueluche/diagnóstico , Coqueluche/transmissão , Adolescente , Adulto , Fatores Etários , Contagem de Células , Tosse/etiologia , Cianose/etiologia , DNA Bacteriano/isolamento & purificação , Família , Feminino , Humanos , Lactente , Recém-Nascido , Leucocitose , Masculino , México/epidemiologia , Pessoa de Meia-Idade , Neutrófilos , Pneumonia/epidemiologia , Estudos Prospectivos , Respiração Artificial , Coqueluche/epidemiologia , Adulto JovemRESUMO
The aim of this study was to identify the presence of group CTX-M-9 extended spectrum beta-lactamases (ESBL) in clinical Escherichia coli isolates from pediatric patients. A total of 404 non-repeated positive ESBL E. coli isolates were collected from documented clinical infections in pediatric patients over a 2-year period. The identification and susceptibility profiles were determined using an automated system. Isolates that suggested ESBL production based on their resistance profiles to third and fourth generation cephalosporin and monobactam were selected. ESBL production was phenotypically confirmed using a diffusion method with cefotaxime and ceftazidime discs alone and in combination with clavulanic acid. blaESBL gene identification was performed through PCR amplification and sequencing. Pulsed Field Gel Electrophoresis (PFGE) and Multilocus Sequence Typing (MLST) were performed to establish the clonal relationships of the E. coli isolates. CTX-M-9-type ESBLs were detected in 2.5% of the isolates. The subtypes corresponded to blaCTX-M-14 (n = 4) and blaCTX-M-27 (n = 6). Additionally, coexistence with other beta-lactamases was observed. A clonal relationship was established in three isolates; the rest were classified as non-related. We found seven different sequence type (ST) in CTX-M-9- producing E. coli isolates. ST38 was the most frequent. This study is the first report in Mexico to document the presence of group CTX-M-9 ESBLs in E. coli isolates from pediatric patients.
Assuntos
Cefotaxima/farmacologia , Ceftazidima/farmacologia , Resistência às Cefalosporinas , Infecções por Escherichia coli , Proteínas de Escherichia coli , Escherichia coli , beta-Lactamases , Adolescente , Resistência às Cefalosporinas/efeitos dos fármacos , Resistência às Cefalosporinas/genética , Criança , Pré-Escolar , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Escherichia coli/enzimologia , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/enzimologia , Infecções por Escherichia coli/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , México , beta-Lactamases/genética , beta-Lactamases/metabolismoRESUMO
Pertussis is a serious respiratory disease in infants that can also affect children and adults. Vaccination against pertussis was introduced in the 1950s and in the 1990s a resurgence of pertussis was observed worldwide. The aim of this work is to summarize the recent data concerning pertussis disease in different countries of Latin America. In this geographic region, pertussis is nationally notifiable and cases should be reported to the appropriate health department/Ministry. Though the surveillance systems are not the same among Latin America countries, over recent decades an increasing number of cases have been detected. Most of these cases correspond to patients younger than 6 months old who received fewer than three doses of vaccine. However, cases in adolescent and adults have also been detected. For this situation, which is not peculiar to Latin America countries, several explanations have been proposed.
Assuntos
Vacina contra Coqueluche/uso terapêutico , Coqueluche/epidemiologia , Monitoramento Epidemiológico , Humanos , Imunidade Coletiva , Imunização Secundária/métodos , Incidência , América Latina/epidemiologia , Vacina contra Coqueluche/administração & dosagem , Coqueluche/prevenção & controleRESUMO
Pediatric oncology and hematology patients are at increased risk of developing healthcare associated infections (HAIs). We conducted a prospective surveillance study on children with cancer admitted to the pediatric hematology and oncology units at a public pediatric hospital in Mexico from January 2004 to December 2009. The incidence of HAIs and groups at greatest risk for HAIs were analyzed. The annual HAI incidence rate and incidence density were calculated. Risk factors such as site of infection, HAI types, and cancer diagnosis were studied. A total of 9420 patients participated, and 409 had HAIs (479 episodes). Annual HAI rates were 3.7 to 5.5 per 100 admissions and the incidence density was 5.75 to 6 HAIs per 1000 inpatient days annually. There were 272 (56.8%) bloodstream infections, 45 (9.4%) pneumonia cases, and 44 (9.2%) skin and soft tissue infections. Children with acute lymphoblastic leukemia had 37.2% and those with acute myeloid leukemia had 16.4% of the HAIs. A total of 11.5% of the HAIs were in children with osteosarcoma. The most common pathogens were Gram-negative bacteria. The HAI-associated mortality rate was 3.7%. Although the overall HAI rate is in line with published reports, the mortality rate was higher, suggesting the incorporation of more aggressive methods to treat infections at our hospital.