ABSTRACT
Abstract We report the first description of a rare catalase-negative strain of Staphylococcus aureus in Chile. This new variant was isolated from blood and synovial tissue samples of a pediatric patient. Sequencing analysis revealed that this catalase-negative strain is related to ST10 strain, which has earlier been described in relation to S. aureus carriers. Interestingly, sequence analysis of the catalase gene katA revealed presence of a novel nonsense mutation that causes premature translational truncation of the C-terminus of the enzyme leading to a loss of 222 amino acids. Our study suggests that loss of catalase activity in this rare catalase-negative Chilean strain is due to this novel nonsense mutation in the katA gene, which truncates the enzyme to just 283 amino acids.
Subject(s)
Child, Preschool , Humans , Codon, Nonsense , Catalase/genetics , Catalase/metabolism , Staphylococcal Infections/microbiology , Staphylococcus aureus/enzymology , Staphylococcus aureus/genetics , Arthritis/microbiology , Bacteremia/microbiology , Chile , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Genotype , Sequence Analysis, DNAABSTRACT
Staphylococcus aureus is a known pathogen in pediatric patients that produces skin infections, cutaneous abscess, cellulitis and osteoarticular infections. Most of these infections are produced by a meticilin susceptible strain. The community associated methicillin resistant Staphylococcus aureus was published for the first time in 1993, ever since then is has been recognized as a cosmopolite pathogen. The first report in Latin America was published in 2003, and in Chile in 2008 from adult patients that have reported traveling to other countries. The following series describes four pediatric cases, all school-aged children, diagnosed since 2012 with clinical followups and molecular studies. Two cases presented as osteomyelitis of the lower extremity; and one presented as arm cellulitis. These three cases had Panton Valentine leukocidine (PV-L) negative strains from the clone complex 8. The last case presented a renal abscess, the strain was PV-L positive from the clone complex 30. This case series constitutes the first pediatric case report in Chile.
Staphylococcus aureus es un patógeno conocido como causa de infecciones de piel, tejidos blandos, osteoarticulares y celulitis en niños. Estas infecciones son principalmente causadas por cepas sensibles a meticilina. Staphylococcus aureus resistente a meticilina asociado a la comunidad fue publicado por primera vez en población australiana nativa en 1993 y desde entonces se ha transformado en un patógeno cosmopolita. En Latinoamérica se publicó el primer caso en 2003 y en Chile se comunicaron los primeros casos en 2008, casi todos adultos y con antecedentes de viaje al extranjero. Nuestra serie describe cuatro casos clínicos en niños escolares, pesquisados desde el 2012 con seguimiento clínico y estudio molecular. Dos casos se presentaron como una osteomielitis de extremidad inferior y uno como una celulitis de brazo. Los tres primeros casos correspondieron a cepas leucocidina Panton Valentine (PV-L) negativa, del complejo clonal 8. El último caso fue un absceso renal, cepa PV-L positiva, perteneciente al complejo clonal 30. Esta serie es el primer reporte de casos pediátricos en Chile.
Subject(s)
Adolescent , Child , Female , Humans , Male , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Staphylococcal Infections/microbiology , Chile/epidemiology , Community-Acquired Infections/epidemiology , Community-Acquired Infections/microbiology , Hospitals, Pediatric , Staphylococcal Infections/epidemiologySubject(s)
Female , Humans , Male , Middle Aged , Meningitis, Bacterial/diagnosis , Meningitis, Bacterial/microbiology , Streptococcal Infections/diagnosis , Streptococcal Infections/microbiology , Streptococcus suis/isolation & purification , Chile/epidemiology , Meningitis, Bacterial/epidemiology , Streptococcal Infections/epidemiology , Streptococcus suis/geneticsABSTRACT
Background: Following the announcement of the Influenza A(H1N1) pandemic by the World Health Organization in April 2009, a surveillance program was carried out in Chile to detect the introduction of the virus in the country and to monitor its propagation and impact. Aim: To describe the onset of the outbreak and the genetic characterization of the pandemic H1N1 influenza virus in the first detected cases in Chile. Material and Methods: Analysis of18 clinical samples coming from suspicious patients, received in a National Reference Laboratory. RNA reverse transcription and real time influenza gene DNA amplification was carried out in a 7500 Fast and Step One Real Time PCR Systems of Applied Biosystems and MxPro-Mx3000P thermocycler from Stratagene. Super Script III Platinum One-Step Quantitative RT-PCR was used. Results: The virus was first detected in three persons returning from the Dominican Republic via Panamá and a child from the east zone of Santiago. Genetic characterization of the virus showed that the child was infected by a different variant of the pandemic virus than the three persons returning from the Caribbean. Conclusions: The onset of the Influenza outbreak in Chile apparently carne from two different epidemiological groups. The spread of the virus detected in the voyagers was limited immediately However the virus of the fourth case was found in different regions of Chile.