RESUMEN
We present the first report, to our knowledge, of a renal abscess cause by an infection from Gordonia terrae in a kidney transplant patient. The patient simultaneously had pulmonary tuberculosis and a perirenal allograft abscess caused by G. terrae. After treatment with imipenem, in addition to anti-tuberculous drugs, the patient was cured.
Asunto(s)
Absceso/microbiología , Infecciones por Actinomycetales/microbiología , Bacteria Gordonia/aislamiento & purificación , Enfermedades Renales/microbiología , Trasplante de Riñón/efectos adversos , Absceso/tratamiento farmacológico , Infecciones por Actinomycetales/tratamiento farmacológico , Antibacterianos/uso terapéutico , Femenino , Bacteria Gordonia/genética , Humanos , Enfermedades Renales/tratamiento farmacológico , Persona de Mediana Edad , ARN Bacteriano/genética , ARN Ribosómico 16S/genéticaRESUMEN
BACKGROUND: Airway inflammation in asthma involves innate immune responses. Toll-like receptors (TLRs) and thymic stromal lymphopoietin (TSLP) are thought to be involved in airway inflammation, but their expression in asthmatics' both large and small airways has not been investigated. OBJECTIVE: To analyse the expression of TLR2, TLR3, TLR4 and TSLP in large and small airways of asthmatics and compare their expression in smoking and non-smoking asthmatics; to investigate whether TLR expression is associated with eosinophilic or neutrophilic airway inflammation and with Mycoplasma pneumoniae and Chlamydophila pneumoniae infection. METHODS: Using immunohistochemistry and image analysis, we investigated TLR2, TLR3, TLR4 and TSLP expression in large and small airways of 24 victims of fatal asthma, FA, (13 non-smokers, 11 smokers) and nine deceased control subjects (DCtrl). TLRs were also measured in 18 mild asthmatics (MA) and 12 healthy controls (HCtrl). M. pneumoniae and C. pneumoniae in autopsy lung tissue were analysed using real-time polymerase chain reaction. Airway eosinophils and neutrophils were measured in all subjects. RESULTS: Fatal asthma patients had higher TLR2 in the epithelial and outer layers of large and small airways compared with DCtrls. Smoking asthmatics had lower TLR2 levels in the inner and outer layers of the small airways than non-smoking asthmatics. TSLP was increased in the epithelial and outer layers of the large airways of FA. FA patients had greater TLR3 expression in the outer layer of large airways and greater TLR4 expression in the outer layer of small airways. Eosinophilic airway inflammation was associated with TLR expression in the epithelium of FA. No bacterial DNA was detected in FA or DCtrls. MA and HCtrls had only a small difference in TLR3 expression. CONCLUSIONS AND CLINICAL RELEVANCE: Increased expression of TLR 2, 3 and 4 and TSLP in fatal asthma may contribute to the acute inflammation surrounding asthma deaths.
Asunto(s)
Asma/mortalidad , Citocinas/metabolismo , Receptor Toll-Like 2/metabolismo , Receptor Toll-Like 3/metabolismo , Receptor Toll-Like 4/metabolismo , Adulto , Asma/inmunología , Femenino , Humanos , Inflamación/inmunología , Pulmón/inmunología , Masculino , Persona de Mediana Edad , Regulación hacia Arriba , Linfopoyetina del Estroma TímicoRESUMEN
Mycobacterium haemophilum is a slow-growing nontuberculous mycobacterium that can cause disease in both immunocompetent and immunocompromised patients. The most common clinical presentations of infection are the appearance of suppurative and ulcerated skin nodules. For the diagnosis, samples collected from suspected cases must be processed under the appropriate conditions, because M. haemophilum requires lower incubation temperatures and iron supplementation in order to grow in culture. In this case report, we describe the occurrence of skin lesions in a kidney transplant recipient, caused by M. haemophilum, associated with acupuncture treatment. The diagnosis was established by direct smear and culture of material aspirated from cutaneous lesions. Species identification was achieved by characterization of the growth requirements and by partial sequencing of the hsp65 gene. The patient was successfully treated with clarithromycin and ciprofloxacin for 12 months. Considering that the number of patients receiving acupuncture treatment is widely increasing, the implications of this potential complication should be recognized, particularly in immunosuppressed patients.
Asunto(s)
Terapia por Acupuntura/efectos adversos , Trasplante de Riñón/efectos adversos , Infecciones por Mycobacterium/microbiología , Mycobacterium haemophilum/aislamiento & purificación , Enfermedades Cutáneas Bacterianas/microbiología , Antibacterianos/uso terapéutico , Ciprofloxacina/uso terapéutico , Claritromicina/uso terapéutico , Humanos , Huésped Inmunocomprometido , Masculino , Persona de Mediana Edad , Infecciones por Mycobacterium/diagnóstico , Infecciones por Mycobacterium/tratamiento farmacológico , Infecciones por Mycobacterium/patología , Mycobacterium haemophilum/clasificación , Mycobacterium haemophilum/genética , Enfermedades Cutáneas Bacterianas/diagnóstico , Enfermedades Cutáneas Bacterianas/tratamiento farmacológico , Enfermedades Cutáneas Bacterianas/patologíaRESUMEN
Antagonistic and synergistic substances are important for interactions between micro-organisms associated with human body surfaces, either in healthy or in diseased conditions. In the present study, such compounds produced by Gardnerella vaginalis strains isolated from women with bacterial vaginosis (BV) were detected in vitro and the antagonistic ones were partially characterized. Among 11 G. vaginalis strains tested, all showed antagonistic activity against at least one of the 22 indicator bacteria assayed. Interestingly, for some of these strains, antagonism reverted to synergism, favouring one of the indicator strains (Peptostreptococcus anaerobius) when the growth medium was changed. Partial characterization of antagonistic substances suggested a bacteriocin-like chemical nature. Depending on growth conditions, G. vaginalis isolated from women with BV produced antagonistic or synergistic compounds for other bacterial components of the vaginal ecosystem. This is the first report to our knowledge of the production of antagonistic and/or synergistic substances by G. vaginalis. This ability may be a pivotal factor in understanding BV and the ecological role of this bacterium in the vaginal environment.
Asunto(s)
Antibiosis , Gardnerella vaginalis/aislamiento & purificación , Gardnerella vaginalis/fisiología , Vaginosis Bacteriana/microbiología , Antibacterianos/biosíntesis , Bacterias/efectos de los fármacos , Bacteriocinas/biosíntesis , Medios de Cultivo/química , Femenino , Gardnerella vaginalis/patogenicidad , Humanos , VirulenciaRESUMEN
The frequency and severity of human infections associated with Corynebacterium ulcerans appear to be increasing in different countries. Here, we describe the first C. ulcerans strain producing a diphtheria-like toxin isolated from an elderly woman with a fatal pulmonary infection and a history of leg skin ulcers in the Rio de Janeiro metropolitan area.
Asunto(s)
Bronconeumonía/microbiología , Infecciones por Corynebacterium/microbiología , Corynebacterium/metabolismo , Toxoide Diftérico/biosíntesis , Úlcera de la Pierna/microbiología , Anciano de 80 o más Años , Brasil/epidemiología , Bronconeumonía/diagnóstico , Corynebacterium/aislamiento & purificación , Infecciones por Corynebacterium/diagnóstico , Infecciones por Corynebacterium/epidemiología , Resultado Fatal , Femenino , Humanos , Úlcera de la Pierna/diagnósticoRESUMEN
The frequency and severity of human infections associated with Corynebacterium ulcerans appear to be increasing in different countries. Here, we describe the first C. ulcerans strain producing a diphtheria-like toxin isolated from an elderly woman with a fatal pulmonary infection and a history of leg skin ulcers in the Rio de Janeiro metropolitan area.
Asunto(s)
Anciano de 80 o más Años , Femenino , Humanos , Bronconeumonía/microbiología , Infecciones por Corynebacterium/microbiología , Corynebacterium/metabolismo , Toxoide Diftérico/biosíntesis , Úlcera de la Pierna/microbiología , Brasil/epidemiología , Bronconeumonía/diagnóstico , Infecciones por Corynebacterium/diagnóstico , Infecciones por Corynebacterium/epidemiología , Corynebacterium/aislamiento & purificación , Resultado Fatal , Úlcera de la Pierna/diagnósticoRESUMEN
SUMMARY: We investigated an outbreak caused by non-tuberculous mycobacteria (NTM) related to breast implant surgery in the city of Campinas, Brazil, by means of a retrospective cohort and molecular epidemiological study. A total of 492 records of individuals having breast surgery in 12 hospitals were evaluated. Twelve isolates were analysed using four different molecular typing methods. There were 14 confirmed cases, 14 possible cases and one probable case. One probable, nine possible and 12 confirmed cases were included in a cohort study; all occurred in eight of the hospitals and the confirmed cases in five. Univariate analysis showed that patients who had had breast reconstruction surgery in hospitals A and B were more likely to have NTM infections. No risk factor was independently associated with NTM infection in the multivariate model. The isolates obtained from patients at each hospital showed different molecular patterns, excluding isolates from hospital C that repeatedly showed the same genotype for approximately one year. In conclusion, this outbreak was caused by polyclonal strains at different institutions, and in one hospital a unique genotype caused most cases. No specific risk factors were found.
Asunto(s)
Implantación de Mama/efectos adversos , Infección Hospitalaria/epidemiología , Brotes de Enfermedades , Infecciones por Mycobacterium/epidemiología , Infección de la Herida Quirúrgica/epidemiología , Adolescente , Adulto , Técnicas de Tipificación Bacteriana , Brasil/epidemiología , Estudios de Cohortes , Infección Hospitalaria/microbiología , ADN Bacteriano/genética , Femenino , Genotipo , Humanos , Persona de Mediana Edad , Epidemiología Molecular , Análisis Multivariante , Infecciones por Mycobacterium/microbiología , Estudios Retrospectivos , Factores de Riesgo , Infección de la Herida Quirúrgica/microbiologíaRESUMEN
A cluster of cases of post-augmentation mammaplasty surgical site infections occurred between 2002 and 2004 in Campinas, in the southern region of Brazil. Rapidly growing mycobacteria were isolated from samples from 12 patients. Eleven isolates were identified as Mycobacterium fortuitum and one as Mycobacterium porcinum by PCR-restriction digestion of the hsp65 gene. These 12 isolates, plus six additional M. fortuitum isolates from non-related patients, were typed by pulsed-field gel electrophoresis (PFGE) and three PCR-based techniques: 16S-23S rRNA internal transcribed spacer (ITS) genotyping; randomly amplified polymorphic DNA (RAPD) PCR; and enterobacterial repetitive intergenic consensus (ERIC) PCR. Four novel M. fortuitum allelic variants were identified by restriction analysis of the ITS fragment. One major cluster, comprising six M. fortuitum isolates, and a second cluster of two isolates, were identified by the four methods. RAPD-PCR and ITS genotyping were less discriminative than ERIC-PCR. ERIC-PCR was comparable to PFGE as a valuable complementary tool for investigation of this type of outbreak.
Asunto(s)
Técnicas de Tipificación Bacteriana , Mamoplastia , Infecciones por Mycobacterium no Tuberculosas/microbiología , Mycobacterium fortuitum/clasificación , Mycobacterium fortuitum/aislamiento & purificación , Infección de la Herida Quirúrgica/microbiología , Proteínas Bacterianas/genética , Brasil , Chaperonina 60 , Chaperoninas/genética , Análisis por Conglomerados , Dermatoglifia del ADN , ADN Bacteriano/genética , ADN Espaciador Ribosómico/genética , Electroforesis en Gel de Campo Pulsado , Femenino , Genotipo , Humanos , Mycobacterium fortuitum/genética , Polimorfismo Genético , Polimorfismo de Longitud del Fragmento de Restricción , Técnica del ADN Polimorfo Amplificado Aleatorio , Infección de la Herida Quirúrgica/epidemiologíaRESUMEN
Ralstonia pickettii and Burkholderia cepacia complex isolates are causes of healthcare-associated infection related to contamination of intravenously administered products. Based on microbiological and epidemiological data and molecular typing by pulsed-field gel electrophoresis, we report the occurrence of two outbreaks of R. pickettii and B. cepacia complex bloodstream infections. The first outbreak occurred from August 1995 to September 1996, and the second outbreak occurred from 28 March to 8 April 1998, affecting adults and neonates, respectively. Infusion of contaminated water for injection was the source of infection.
Asunto(s)
Bacteriemia/etiología , Infecciones por Burkholderia/etiología , Complejo Burkholderia cepacia , Infección Hospitalaria/etiología , Contaminación de Medicamentos , Infecciones por Bacterias Gramnegativas/etiología , Inyecciones/efectos adversos , Ralstonia , Microbiología del Agua , Adulto , Bacteriemia/epidemiología , Brasil/epidemiología , Infecciones por Burkholderia/epidemiología , Complejo Burkholderia cepacia/clasificación , Complejo Burkholderia cepacia/genética , Complejo Burkholderia cepacia/aislamiento & purificación , Infección Hospitalaria/epidemiología , ADN Bacteriano/análisis , ADN Bacteriano/genética , Brotes de Enfermedades/estadística & datos numéricos , Electroforesis en Gel de Campo Pulsado , Resultado Fatal , Femenino , Genotipo , Infecciones por Bacterias Gramnegativas/epidemiología , Humanos , Recién Nacido , Control de Infecciones , Masculino , Epidemiología Molecular , Filogenia , Ralstonia/clasificación , Ralstonia/genética , Ralstonia/aislamiento & purificación , Estaciones del AñoRESUMEN
AIMS: To investigate phenotypic aspects including biotyping, drug susceptibility and production of extracellular enzymes and genetic diversity of Stenotrophomonas maltophilia clinical strains obtained from seven hospitals in Rio de Janeiro, Brazil. METHODS AND RESULTS: Thirty-nine S. maltophilia strains were investigated by biotying, susceptibility testing, extracellular enzymes detection and by randomly amplified polymorphic DNA (RAPD)-PCR. Biotyping distinguished 13 biotypes among 39, and one of them was prevalent. The majority of the strains produced DNase, gelatinase and haemolysin. Protease, lipases and phospholipase C activities were observed in highly variable amounts. None of the strains was elastase producer. The percentage of full susceptibility, by agar dilution, was 100, 94.8, 81.6 and 26.3% for trimethoprim/sulphametoxazole, ticarcillin/clavulanate, ciprofloxacin and ceftazidime, respectively. Thirty-three RAPD-PCR profiles were obtained suggesting multiple sources of acquisition. CONCLUSIONS: The results pointed out the necessity of monitoring S. maltophilia especially in critical hospital wards, to assure effective control measures. SIGNIFICANCE AND IMPACT OF THE STUDY: Despite of the genetic diversity among the strains, in two situations it was observed indistinguishable RAPD-PCR profiles among strains isolated from different patients who had been hospitalized in the same hospital ward, suggesting the possibility of nosocomial transmission that until now has been rarely related.
Asunto(s)
Stenotrophomonas maltophilia/genética , Animales , Antibacterianos/farmacología , Técnicas de Tipificación Bacteriana/métodos , Brasil , Infección Hospitalaria/microbiología , Infección Hospitalaria/prevención & control , ADN Bacteriano/análisis , Farmacorresistencia Bacteriana , Endopeptidasas/metabolismo , Infecciones por Bacterias Gramnegativas/microbiología , Infecciones por Bacterias Gramnegativas/prevención & control , Hemólisis/fisiología , Humanos , Fenotipo , Filogenia , Reacción en Cadena de la Polimerasa/métodos , Polimorfismo Genético/genética , Conejos , Ovinos , Stenotrophomonas maltophilia/efectos de los fármacos , Stenotrophomonas maltophilia/enzimologíaRESUMEN
An outbreak of extended spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBLKp) infections in a neonatal intensive care unit (NICU) prompted a prospective investigation of colonization and infection with this pathogen. From August 1, 1997 to May 30, 1999, neonates admitted to the NICU for more than 24 h were screened for ESBLKp acquisition. Neonatal gastrointestinal screening was performed by means of faecal sampling within 48 h of admission and then weekly until discharge. Isolates were typed using pulsed-field gel electrophoresis (PFGE). Time-dependent proportional hazard models were used to identify independent effects of invasive procedures and antimicrobials after controlling for duration of stay at the NICU. During the study period, 464 neonates were admitted and 383 were regularly screened. Infections occurred in 13 (3.4%) neonates and 206 (53.8%) became colonized. Independent risk factors for colonization during the first nine days in the NICU were the antimicrobial combination cephalosporin plus aminoglycoside [hazard rate (HR)=4.60; 95% CI: 1.48-14.31], and each NICU-day was associated with a 26% increase in the hazard rate for colonization (HR=1.26; 95% CI: 1.16-1.37). Previous colonization (HR=5.19; 95% CI: 1.58-17.08) and central vascular catheter use (HR=13.89; 95% CI: 2.71-71.3) were independent risk factors for infection. In an outbreak setting the proportion of neonates colonized with ESBLKp was observed to increase with the duration of stay and antimicrobial use, and once colonized, infants exposed to invasive devices may become infected.
Asunto(s)
Portador Sano , Infección Hospitalaria/etiología , Brotes de Enfermedades/estadística & datos numéricos , Unidades de Cuidado Intensivo Neonatal , Infecciones por Klebsiella/etiología , Klebsiella pneumoniae , beta-Lactamasas , Antibacterianos/efectos adversos , Brasil/epidemiología , Portador Sano/epidemiología , Portador Sano/prevención & control , Cateterismo Venoso Central/efectos adversos , Análisis por Conglomerados , Infección Hospitalaria/epidemiología , Infección Hospitalaria/prevención & control , Brotes de Enfermedades/prevención & control , Femenino , Hospitales con 100 a 299 Camas , Hospitales Privados , Humanos , Incidencia , Lactante , Recién Nacido , Control de Infecciones/métodos , Infecciones por Klebsiella/epidemiología , Infecciones por Klebsiella/prevención & control , Klebsiella pneumoniae/clasificación , Klebsiella pneumoniae/enzimología , Klebsiella pneumoniae/genética , Tiempo de Internación/estadística & datos numéricos , Masculino , Tamizaje Masivo , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Factores de Riesgo , Estaciones del Año , SerotipificaciónRESUMEN
Mycobacterium simiae is usually an environmental contaminant rarely associated with human disease. We report a fatal case of M.simiae infection in a 37 year old, HIV positive, male from whom the organism was isolated from blood culture. The identification of M.simiae was performed using DNA amplification followed by analysis on 3 agarose gel of the amplicon fragments after digestion by restriction endonucleases. The precise identification of mycobacterial isolates to the species level is important, with both epidemiological and therapeutic implications.
Asunto(s)
Humanos , Masculino , Adulto , Infecciones Oportunistas Relacionadas con el SIDA/microbiología , Mycobacterium , Infecciones por Mycobacterium , Resultado Fatal , Mycobacterium , Polimorfismo de Longitud del Fragmento de RestricciónRESUMEN
Three clinical strains (Escherichia coli Rio-6, E. coli Rio-7, and Enterobacter cloacae Rio-9) collected in 1996 and 1999 from hospitals in Rio de Janeiro (Brazil) were resistant to broad-spectrum cephalosporins and gave a positive double-disk synergy test. Two bla(CTX-M) genes encoding beta-lactamases of pl 7.9 and 8.2 were implicated in this resistance: the bla(CTX-M-9) gene observed in E. coli Rio-7 and E. cloacae Rio-9 and a novel CTX-M-encoding gene, designated bla(CTX-M-16), observed in E. coli strain Rio-6. The deduced amino acid sequence of CTX-M-16 differed from CTX-M-9 only by the substitution Asp-240-->Gly. The CTX-M-16-producing E. coli transformant exhibited the same level of resistance to cefotaxime (MIC, 16 microg/ml) but had a higher MIC of ceftazidime (MIC, 8 versus 1 microg/ml) than the CTX-M-9-producing transformant. Enzymatic studies revealed that CTX-M-16 had a 13-fold higher affinity for aztreonam and a 7.5-fold higher k(cat) for ceftazidime than CTX-M-9, thereby showing that the residue in position 240 can modulate the enzymatic properties of CTX-M enzymes. The two bla(CTX-M-9) genes and the bla(CTX-M-16) gene were located on different plasmids, suggesting the presence of mobile elements associated with CTX-M-encoding genes. CTX-M-2 and CTX-M-8 enzymes were found in Brazil in 1996, and two other CTX-M beta-lactamases, CTX-M-9 and CTX-M-16, were subsequently observed. These reports are evidence of the diversity of CTX-M-type extended-spectrum beta-lactamases in Brazil.
Asunto(s)
Sustitución de Aminoácidos/genética , Cefotaxima/farmacología , Resistencia a las Cefalosporinas/genética , Cefalosporinas/farmacología , Enterobacteriaceae/enzimología , Mutación , beta-Lactamasas/genética , Secuencia de Aminoácidos , Ácido Aspártico/genética , Brasil , ADN Bacteriano/análisis , Farmacorresistencia Microbiana , Enterobacteriaceae/efectos de los fármacos , Enterobacteriaceae/genética , Escherichia coli/efectos de los fármacos , Escherichia coli/enzimología , Escherichia coli/genética , Técnicas de Transferencia de Gen , Glicina/genética , Humanos , Datos de Secuencia Molecular , Homología de Secuencia de Aminoácido , beta-Lactamasas/metabolismoRESUMEN
Mycobacterium simiae is usually an environmental contaminant rarely associated with human disease. We report a fatal case of M.simiae infection in a 37 year old, HIV positive, male from whom the organism was isolated from blood culture. The identification of M.simiae was performed using DNA amplification followed by analysis on 3% agarose gel of the amplicon fragments after digestion by restriction endonucleases. The precise identification of mycobacterial isolates to the species level is important, with both epidemiological and therapeutic implications.
Asunto(s)
Infecciones Oportunistas Relacionadas con el SIDA/microbiología , Infecciones por Mycobacterium/microbiología , Mycobacterium/aislamiento & purificación , Adulto , Resultado Fatal , Humanos , Masculino , Mycobacterium/clasificación , Mycobacterium/genética , Polimorfismo de Longitud del Fragmento de RestricciónRESUMEN
Serratia marcescens Rio-5, one of 18 extended-spectrum beta-lactamase (ESBL)-producing strains isolated in several hospitals in Rio de Janeiro (Brazil) in 1996 and 1997, exhibited a high level of resistance to aztreonam (MIC, 512 microgram/ml) and a distinctly higher level of resistance to cefotaxime (MIC, 64 microgram/ml) than to ceftazidime (MIC, 8 microgram/ml). The strain produced a plasmid-encoded ESBL with a pI of 7.5 whose bla gene was not related to those of other plasmid-mediated Ambler class A ESBLs. Cloning and sequencing revealed a bla gene encoding a novel class A beta-lactamase in functional group 2be, designated BES-1 (Brazil extended-spectrum beta-lactamase). This enzyme had 51% identity with chromosomal class A penicillinase of Yersinia enterocolitica Y56, which was the most closely related enzyme and 47 to 48% identity with CTX-M-type beta-lactamases, which were the most closely related ESBLs. In common with CTX-M enzymes, BES-1 exhibited high cefotaxime-hydrolyzing activity (k(cat), 425 s(-1)). However, BES-1 differed from CTX-M enzymes by its significant ceftazidime-hydrolyzing activity (k(cat), 25 s(-1)), high affinity for aztreonam (K(i), 1 microM), and lower susceptibility to tazobactam (50% inhibitory concentration [IC(50)], 0.820 microM) than to clavulanate (IC(50), 0.045 microM). Likewise, certain characteristic structural features of CTX-M enzymes, such as Phe-160, Ser-237, and Arg-276, were observed for BES-1, which, in addition, harbored different residues (Ala-104, Ser-171, Arg-220, Gly-240) and six additional residues at the end of the sequence. BES-1, therefore, may be an interesting model for further investigations of the structure-function relationships of class A ESBLs.
Asunto(s)
Serratia marcescens/genética , Resistencia betalactámica/genética , beta-Lactamasas/genética , Secuencia de Aminoácidos , Secuencia de Bases , Brasil , Clonación Molecular , Humanos , Pruebas de Sensibilidad Microbiana , Datos de Secuencia Molecular , Filogenia , Homología de Secuencia de Aminoácido , Serratia marcescens/efectos de los fármacos , Serratia marcescens/enzimología , Serratia marcescens/metabolismo , beta-Lactamasas/metabolismo , beta-Lactamas/farmacologíaRESUMEN
The present study used two molecular typing methods to investigate a cluster of eight cases of Candida parapsilosis fungemia in a hospital in Rio de Janeiro, Brazil. Candida parapsilosis is an important opportunistic pathogen that is frequently involved in outbreaks of nosocomial fungemia. Identification of a common source of infection and determination of genetic relatedness among the strains involved in outbreaks are important for infection control. Candida parapsilosis strains were isolated from the bloodstream of patients housed in an intensive-care unit (n=5) and in individual rooms (n=3). An additional strain of Candida parapsilosis was isolated from a hyperalimentation infusion flask, which was implicated by molecular typing to be the source of infection. All strains were identified using morphological and biochemical methods. The genetic relationship between patients' strains and the hyperalimentation infusion strain was assessed by electrophoretic karyotype (EK) analysis and random amplification of polymorphic DNA (RAPD). Both methods resulted in patterns that allowed differentiation of the isolates. Candida parapsilosis fungemia, in three of the eight patients, resulted from a common source of infection, as demonstrated by molecular typing methods. Image analysis of EK patterns indicated that these strains were closest to Candida parapsilosis Group II, a grouping that is a less frequent clinical isolate than the major Group I strains.
Asunto(s)
Candida/clasificación , Fungemia/microbiología , Técnicas de Tipificación Micológica , Candida/efectos de los fármacos , ADN de Hongos/análisis , Fungemia/genética , Pruebas de Sensibilidad Microbiana , Técnica del ADN Polimorfo Amplificado AleatorioRESUMEN
To estimate the diversity of extended-spectrum beta-lactamases in Brazil, 18 strains from different species of the family Enterobacteriaceae exhibiting a positive double-disk synergy test were collected by a clinical laboratory from several hospitals in Rio de Janeiro, Brazil, in 1996 and 1997. Four strains (Proteus mirabilis, Enterobacter cloacae, Enterobacter aerogenes, and Citrobacter amalonaticus) hybridized with a 550-bp CTX-M probe. The P. mirabilis strain produced a CTX-M-2 enzyme. The E. cloacae, E. aerogenes, and C. amalonaticus isolates harbored a bla gene which was identified by cloning and sequencing as a bla(CTX-M) gene. E. coli HB101 transconjugants and the E. coli DH5alpha transformant harboring a recombinant plasmid produced a CTX-M beta-lactamase with an isoelectric point of 7.6 conferring a resistance phenotype characterized by a higher level of resistance to cefotaxime than to ceftazidime, as observed with the other CTX-M enzymes. The deduced protein sequence showed a novel Ambler class A CTX-M enzyme, named CTX-M-8, which had 83 to 88% identity with the previously described CTX-M enzymes. The phylogenic study of the CTX-M family including CTX-M-8 revealed four CTX-M types, CTX-M-8 being the first member of a new phylum of CTX-M enzymes. The evolutionary distances between the four types of CTX-M were large, suggesting that the four clusters branched off early from a distant unknown enzyme and that intermediate enzymes probably existed.
Asunto(s)
Proteínas Bacterianas , Cefotaxima/farmacología , Resistencia a las Cefalosporinas/genética , Enterobacteriaceae/enzimología , beta-Lactamasas/genética , Secuencia de Aminoácidos , Secuencia de Bases , Brasil , Cefalosporinas/farmacología , Clonación Molecular , ADN Bacteriano/análisis , Enterobacteriaceae/efectos de los fármacos , Enterobacteriaceae/genética , Técnicas de Transferencia de Gen , Humanos , Cinética , Datos de Secuencia Molecular , Homología de Secuencia de Aminoácido , beta-Lactamasas/clasificación , beta-Lactamasas/metabolismo , beta-Lactamas/farmacologíaRESUMEN
The in vitro activity of cefepime was compared to that of ceftazidime, ceftriaxone, and cefotaxime in a multicenter study involving 10 clinical microbiology laboratories and clinical isolates from 18 Brazilian hospitals from 7 cities (4 states). A total of 982 isolates consecutively collected between December 1995 and March 1996 were susceptibility tested by using Etest and following the NCCLS procedures for agar diffusion tests. The cefepime spectrum was broader than that of the other broad-spectrum cephalosporins against both Gram-negative rods and Gram-positive cocci. Cefepime was particularly more active against Enterobacter sp. (MIC90, 2 micrograms/ml), Serratia sp. (MIC90, 2 micrograms/ml) and oxacillin-susceptible Staphylococcus aureus (MIC90, 3 micrograms/ml). Against Pseudomonas aeruginosa, cefepime (MIC90, 16 micrograms/ml) was slightly more active than ceftazidime (MIC90, 32 micrograms/ml) and 8- to 16-fold more active than ceftriaxone of cefotaxime (MIC90, > 256 micrograms/ml). Our results show that nosocomial bacteria, especially Gram-negative rods, have a high rate of cephalosporin resistance in Brazil. However, part of these resistant bacteria remains susceptible to cefepime. The Etest was shown to be an excellent method for multicenter studies of the in vitro evaluation of new antimicrobial agents.