Assuntos
Complemento C3/análise , Infecções por Escherichia coli/complicações , Síndrome Hemolítico-Urêmica/sangue , Doenças do Sistema Nervoso/epidemiologia , Criança , Infecções por Escherichia coli/sangue , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/microbiologia , Síndrome Hemolítico-Urêmica/imunologia , Síndrome Hemolítico-Urêmica/microbiologia , Humanos , Doenças do Sistema Nervoso/imunologia , Curva ROC , Valores de Referência , Medição de Risco/métodos , Escherichia coli Shiga Toxigênica/imunologiaRESUMO
INTRODUCTION: Escherichia coli (E. coli) is a very common uro-pathogen and pathogen of bloodstream infections (BSI) in Jamaica. The aim of this study was to examine this organism's prevalence, determine co-infection rates and assess antibiotic resistance patterns. METHODOLOGY: In the absence of automated systems, data on all E. coli isolates identified at the University Hospital of the West Indies in Kingston, Jamaica during the first six months of 2008 and 2012 was collected and sorted. Data were analyzed using IBM SPSS Statistics version 20 for Windows. RESULTS: A total of 1188 isolates (1072 from urine and 116 from blood) was analyzed. Patients with E. coli BSI were older than those with E. coli urinary tract infections (UTI) (55.3 years vs 42.4 years, p < 0.05) and both had a female predominance. Sensitivity profiles in 2012 for E. coli in blood and urine were highest for the carbapenems, Amikacin and Nitrofurantoin and lowest for the fluoroquinolones and Trimethoprim-sulfamethoxazole. Based on antimicrobial susceptibility patterns, Nitrofurantoin was identified as an appropriate choice for empiric therapy for UTI. Ten antibiotics were noted in this study to have developed statistically significant antibiotic resistance. Patients with E. coli BSI had a co-infection E. coli UTI rate of 39%. CONCLUSIONS: Resistance patterns change drastically in a few years making frequent antimicrobial susceptibility profiling necessary. Further studies would be beneficial in guiding management of these patients.
Assuntos
Coinfecção/epidemiologia , Farmacorresistência Bacteriana Múltipla , Infecções por Escherichia coli/epidemiologia , Escherichia coli/efeitos dos fármacos , Infecções Urinárias/epidemiologia , Infecções Urinárias/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos , Criança , Pré-Escolar , Coinfecção/microbiologia , Estudos Transversais , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/sangue , Infecções por Escherichia coli/microbiologia , Feminino , Hospitais , Humanos , Lactente , Recém-Nascido , Jamaica/epidemiologia , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Prevalência , Urina/microbiologia , Índias Ocidentais/epidemiologia , Adulto JovemRESUMO
The aim of this study was to determine whether oxidative stress occurs in Escherichia coli-infected broiler breeder chicks, as well as the impact of this infection on bird growth. Twenty birds, 25-day-old female birds were divided into two groups (nâ¯=â¯10 per group): an intraperitoneally-infected group (1â¯mL containing 1.5â¯×â¯108â¯CFU of E. coli) and a control group that received 1â¯mL of culture medium (uninfected birds). Birds were weighed individually at the beginning and at the end of the experiment, and samples were collected on days 0, 5 and 10 post-infection (PI). No clinical signs were observed throughout the experimental period; nevertheless, on day 10 PI, there was lower growth and weight gain in infected birds than in the control group. The infected birds showed pericarditis and liver congestion, as well as moderate periportal inflammatory infiltrates with predominance of neutrophils. Significantly higher numbers of total leukocytes, lymphocytes, heterophils and monocytes were observed in the infected group on days 5 and 10 PI, as well as significantly higher total protein and globulin levels; albumin values significantly decreased over the same period. Levels of serum oxidative biomarkers (lipid peroxidation (TBARS) and free radicals (ROS)) were significantly higher at 10 PI, as was glutathione S-transferase (GST) activity during the same period. Hepatic ROS and protein thiol levels were significantly higher in E. coli-infected birds, as well as activities of the antioxidant enzymes catalase, superoxide dismutase. In the spleen, only GST activity was significantly higher for the infected group, unlike the brain, where SOD activity, ROS and non-protein thiol levels were significantly higher in infected birds than in the control group. These data suggested that colibacillosis causes oxidative stress in broiler breeder chicks, negatively affecting their weight gain.
Assuntos
Infecções por Escherichia coli/metabolismo , Estresse Oxidativo/fisiologia , Doenças das Aves Domésticas/metabolismo , Aumento de Peso/fisiologia , Animais , Antioxidantes/análise , Biomarcadores/sangue , Encéfalo/metabolismo , Encéfalo/patologia , Catalase/sangue , Galinhas , Escherichia coli , Infecções por Escherichia coli/sangue , Infecções por Escherichia coli/patologia , Feminino , Radicais Livres , Glutationa Transferase/sangue , Peroxidação de Lipídeos , Fígado/metabolismo , Fígado/patologia , Doenças das Aves Domésticas/sangue , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/patologia , Baço/metabolismo , Baço/patologia , Superóxido Dismutase , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismoRESUMO
OBJECTIVE: This report described the first Escherichia coli (E. coli) isolates harbouring mcr-1 in Uruguay. METHODS: Three E. coli isolates were obtained from blood, urine and rectal swabs from different patients in two hospitals. Extended-spectrum ß-lactamases (ESBL), plasmid-encoded (pAmpC) ß-lactamases, plasmid-mediated quinolone resistance (PMQR) genes, class 1 integrons, and mcr-1, mcr-2 and mcr-3 were sought and characterised in three E. coli isolates. Transfer of resistance determinants was assessed by conjugation. Clonality was analysed by multilocus sequence typing. RESULTS: All isolates were categorised as being colistin-resistant and the mcr-1 gene was detected. Two isolates were also resistant to oxyimino cephalosporins: one on account of blaCMY-2 and the other due to blaCTX-M-15, the latter also harbouring transferable quinolone-resistance genes (aac(6')Ib-cr and qnrB). All mcr-1 genes were transferred by conjugation to recipient strains. The mcr-1-bearing isolates belonged to sequence types ST10, ST93 and ST5442. CONCLUSIONS: ST10 is considered as a high-risk clone worldwide. This type of mcr-1-harbouring clone is a major concern for human and animal health and must be under close surveillance. This study detected the presence of mcr-1 for the first time in Uruguay, albeit in an allodemic manner, associated with different antibiotic-resistance genes and from diverse clinical contexts. Considering that colistin is often the last therapeutic option available for multidrug-resistant Gram-negative bacilli infections, it is important to maximise precautions to avoid dissemination of isolates carrying mcr-1.
Assuntos
Farmacorresistência Bacteriana , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Escherichia coli/classificação , Adulto , Idoso de 80 Anos ou mais , Cefalosporinas/farmacologia , Colistina/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/sangue , Infecções por Escherichia coli/urina , Feminino , Transferência Genética Horizontal , Humanos , Masculino , Tipagem de Sequências Multilocus , Reto/microbiologia , Estudos Retrospectivos , Uruguai/epidemiologiaRESUMO
OBJECTIVES: (1) Evaluate mortality rate in patients with Shiga toxin-producing Escherichia coli hemolytic uremic syndrome, (2) determine the leading causes of death, and (3) identify predictors of mortality at hospital admission. METHODS: We conducted a multicentric, observational, retrospective, cross-sectional study. It included patients under 18 years old with Shiga toxin-producing Escherichia coli hemolytic uremic syndrome hospitalized between January 2005 and June 2016. Clinical and laboratory data were obtained from the Argentine National Epidemiological Surveillance System of Hemolytic Uremic Syndrome. Clinical and laboratory variables were compared between deceased and non-deceased patients. Univariate and multivariate analyses were performed. ROC curves and area under the curve were obtained. RESULTS: Seventeen (3.65%) out of the 466 patients died, being central nervous system involvement the main cause of death. Predictors of death were central nervous system involvement, the number of days since the beginning of diarrhea to hospitalization, hyponatremia, high hemoglobin, high leukocyte counts, and low bicarbonate concentration on admission. In the multivariate analysis, central nervous system involvement, sodium concentration, and hemoglobin were independent predictors. The best cut off for sodium was ≤ 128 meq/l and for hemoglobin ≥ 10.8 g/dl. CONCLUSIONS: Mortality was low in children with Shiga toxin-producing Escherichia coli hemolytic uremic syndrome, being central nervous system involvement the main cause of death. The best mortality predictors found were central nervous system involvement, hemoglobin, and sodium concentration. Hyponatremia may be a new Shiga toxin-producing Escherichia coli hemolytic uremic syndrome mortality predictor.
Assuntos
Infecções por Escherichia coli/mortalidade , Síndrome Hemolítico-Urêmica/mortalidade , Hiponatremia/mortalidade , Doenças do Sistema Nervoso/mortalidade , Escherichia coli Shiga Toxigênica/isolamento & purificação , Pré-Escolar , Estudos Transversais , Infecções por Escherichia coli/sangue , Infecções por Escherichia coli/complicações , Infecções por Escherichia coli/microbiologia , Feminino , Hemoglobinas/análise , Síndrome Hemolítico-Urêmica/sangue , Síndrome Hemolítico-Urêmica/complicações , Síndrome Hemolítico-Urêmica/microbiologia , Humanos , Hiponatremia/sangue , Hiponatremia/diagnóstico , Hiponatremia/etiologia , Lactente , Masculino , Doenças do Sistema Nervoso/sangue , Doenças do Sistema Nervoso/diagnóstico , Doenças do Sistema Nervoso/etiologia , Prognóstico , Curva ROC , Estudos Retrospectivos , Medição de Risco , Sódio/sangueRESUMO
Nowadays acute gastroenteritis infection caused by Escherichia coli (E. coli) O157:H7 is frequently associated with hemolytic uremic syndrome (HUS), which usually developed after prodromal diarrhea that is often bloody. The abdominal pain accompanied by failure kidney is a suspicious symptom to develop this disorder. Their pathological characteristic is vascular damage which manifested as arteriolar and capillary thrombosis with abnormalities in the endothelium and vessel walls. The major etiological agent of HUS is enterohemorragic (E coli) strain belonging to serotype O157:H7. The lack of papers about HUS associated to gastroenteritis lead us to report this case for explain the symptoms that are uncommon. Furthermore, this report provides some strategies to suspect and make an early diagnosis, besides treatment approach to improving outcomes and prognosis for patients with this disorder.
Assuntos
Infecções por Escherichia coli/diagnóstico , Escherichia coli O157/isolamento & purificação , Gastroenterite/diagnóstico , Síndrome Hemolítico-Urêmica/diagnóstico , Dor Abdominal/diagnóstico , Dor Abdominal/microbiologia , Dor Abdominal/terapia , Antibacterianos/uso terapêutico , Diarreia/sangue , Diarreia/diagnóstico , Diarreia/microbiologia , Diarreia/terapia , Infecções por Escherichia coli/sangue , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/terapia , Feminino , Gastroenterite/sangue , Gastroenterite/microbiologia , Gastroenterite/terapia , Síndrome Hemolítico-Urêmica/sangue , Síndrome Hemolítico-Urêmica/microbiologia , Síndrome Hemolítico-Urêmica/terapia , Humanos , Pessoa de Meia-Idade , Contagem de Plaquetas , Diálise RenalRESUMO
Hemolytic uremic syndrome (HUS) is defined as a triad of noninmune microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. The most frequent presentation is secondary to Shiga toxin (Stx)-producing Escherichia coli (STEC) infections, which is termed postdiarrheal, epidemiologic or Stx-HUS, considering that Stx is the necessary etiological factor. After ingestion, STEC colonize the intestine and produce Stx, which translocates across the intestinal epithelium. Once Stx enters the bloodstream, it interacts with renal endothelial and epithelial cells, and leukocytes. This review summarizes the current evidence about the involvement of inflammatory components as central pathogenic factors that could determine outcome of STEC infections. Intestinal inflammation may favor epithelial leakage and subsequent passage of Stx to the systemic circulation. Vascular damage triggered by Stx promotes not only release of thrombin and increased fibrin concentration but also production of cytokines and chemokines by endothelial cells. Recent evidence from animal models and patients strongly indicate that several immune cells types may participate in HUS physiopathology: neutrophils, through release of proteases and reactive oxygen species (ROS); monocytes/macrophages through secretion of cytokines and chemokines. In addition, high levels of Bb factor and soluble C5b-9 (sC5b-9) in plasma as well as complement factors adhered to platelet-leukocyte complexes, microparticles and microvesicles, suggest activation of the alternative pathway of complement. Thus, acute immune response secondary to STEC infection, the Stx stimulatory effect on different immune cells, and inflammatory stimulus secondary to endothelial damage all together converge to define a strong inflammatory status that worsens Stx toxicity and disease.
Assuntos
Infecções por Escherichia coli/imunologia , Síndrome Hemolítico-Urêmica/imunologia , Microvasos/patologia , Escherichia coli Shiga Toxigênica/imunologia , Animais , Via Alternativa do Complemento/imunologia , Citocinas/imunologia , Citocinas/metabolismo , Modelos Animais de Doenças , Células Endoteliais/imunologia , Células Endoteliais/patologia , Endotélio Vascular/citologia , Endotélio Vascular/imunologia , Endotélio Vascular/patologia , Células Epiteliais/imunologia , Células Epiteliais/patologia , Infecções por Escherichia coli/sangue , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/patologia , Síndrome Hemolítico-Urêmica/sangue , Síndrome Hemolítico-Urêmica/microbiologia , Síndrome Hemolítico-Urêmica/patologia , Humanos , Mucosa Intestinal/microbiologia , Rim/irrigação sanguínea , Rim/imunologia , Rim/patologia , Microvasos/citologia , Microvasos/imunologia , Escherichia coli Shiga Toxigênica/isolamento & purificaçãoRESUMO
Hemolysin (HlyA) produced by some stains of Escherichia coli is considered to be an important virulence factor of those bacteria. On the other hand, reactive oxygen species (ROS) have been reported to be involved in the pathogenesis of different diseases via oxidative stress generation. The purpose of this study was to analyze the capacity of HlyA to induce oxidative stress in whole blood cultures (WBCs). To this end, ROS production, the damage induced in lipids and proteins, and the antioxidant defense system was evaluated in blood cultures exposed to low concentrations of HlyA. We found that HlyA increased the level of free radicals detected by chemiluminescence assay. Moreover, lipid peroxidation and protein damage was significantly increased in cultures treated with HlyA in comparation with those found in control cultures. On the other hand, a decrease in total antioxidant capacity of plasma and in the activity of superoxide dismutase (SOD) was observed in plasma from blood treated with HlyA. Collectively, our data demonstrate that low concentrations of E. coli hemolysin induced oxidative stress in WBCs with the induction of different oxidative damage biomarkers.
Assuntos
Infecções por Escherichia coli/sangue , Proteínas de Escherichia coli/sangue , Escherichia coli/química , Proteínas Hemolisinas/sangue , Estresse Oxidativo/efeitos dos fármacos , Produtos da Oxidação Avançada de Proteínas/metabolismo , Antioxidantes/metabolismo , Biomarcadores/sangue , Infecções por Escherichia coli/metabolismo , Infecções por Escherichia coli/microbiologia , Humanos , Peroxidação de Lipídeos , Luminescência , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismoRESUMO
Escherichia coli Vacuolating Factor (ECVF) is a heat-labile, vacuolating cytotoxin produced by avian pathogenic E. coli (APEC) isolated from avian cellulitis lesions. In this report, we intend to demonstrate that purified ECVF induces the inflammatory process of cellulitis. Our group is the first to demonstrate the effect of ECVF in a histological analysis by in situ inoculation of broiler chickens with purified ECVF. The animals were inoculated with the APEC AC53 and with purified ECVF subcutaneously on their ventral surface (in the sternum region). The histological analysis showed different grades of an acute inflammatory response in the epidermis, dermis and panniculus. An increase in mRNA expression of the proinflammatory cytokine TNF-α was also demonstrated in the inflamed tissue. When ECVF was systemically administered, increased levels of TNF-α and IL-10 were observed in the serum. These results suggest that ECVF plays a key role in the inflammatory process associated with cellulitis that is mainly mediated by TNF-α. In addition, this inflammation can be downregulated by the anti-inflammatory cytokine IL-10.
Assuntos
Toxinas Bacterianas/biossíntese , Toxinas Bacterianas/toxicidade , Celulite (Flegmão)/veterinária , Infecções por Escherichia coli/veterinária , Escherichia coli/metabolismo , Doenças das Aves Domésticas/induzido quimicamente , Doenças das Aves Domésticas/microbiologia , Animais , Celulite (Flegmão)/sangue , Celulite (Flegmão)/induzido quimicamente , Celulite (Flegmão)/microbiologia , Embrião de Galinha , Galinhas , Escherichia coli/genética , Infecções por Escherichia coli/sangue , Infecções por Escherichia coli/induzido quimicamente , Infecções por Escherichia coli/microbiologia , Interleucina-10/biossíntese , Interleucina-10/sangue , Interleucina-10/genética , Masculino , Doenças das Aves Domésticas/sangue , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/sangue , Fator de Necrose Tumoral alfa/genéticaRESUMO
Enterotoxigenic Escherichia coli (ETEC) are a major cause of diarrheal disease in humans, calves and pigs. In humans, these infections mainly occur in developing countries leading to a high diarrheal morbidity and infant mortality and to travellers' diarrhea. ETEC strains constitute a phenotypically and genetically diverse pathotype with as common characteristics the production of heat-labile (LT) and/or heat-stable enterotoxins (ST) as well as of one or more fimbrial colonization factors. Despite the global importance of these pathogens, a broadly ETEC protective vaccine is not yet available, partially due to the lack of a suitable animal model for human ETEC. Such model would allow to test more ETEC molecules as potential vaccine candidates. The C57-CD40 ligand deficient (C57-cd40l(-/-)) mouse has been successfully used to develop infection models of intestinal pathogens, but little is known about its humoral immune response. Therefore, the aims of this study were to characterize the humoral immune response of C57 and C57-cd40l(-/-) mice and to determine the persistence of ETEC H10407 and two of its variants after oral inoculation. The serum IgM, IgG and IgA and faecal IgG and IgA concentrations, of twelve mice per mouse strain (C57 and C57-cd40l(-/-)), were determined by ELISA. All serum immunoglobulins and the faecal IgG concentration were significantly lower in C57-cd40l(-/-) than in C57 mice. In contrast the faecal IgA concentration was significantly higher in the C57-cd40l(-/-) mice. This high intestinal IgA concentration might be a compensatory T cell-independent production of IgA production. Both mouse strains were orally inoculated with 5×10(8) ETEC H10407 (LT(+), ST-colonization factor antigen I (CFA/I)(+)) and ETEC in animal faeces was established by culture followed by st and lt loci identification by PCR until day 14 post infection. Most C57 mice eliminated the strain within 3 days whereas infection remained in C57-cd40l(-/-) mice until day 14. Subsequently both mouse strains were inoculated with ETEC H10407 variants and followed up until day 113. Likewise C57 mice eliminated both ETEC variants within 4 days. All C57-cd40l(-/-) mice had eliminated the LT(-) variant at day 31, whereas the ST-CFA/I(-) variant remained in mice stools until day 113. These observations suggest that C57-cd40l(-/-) mice are permissive for ETEC H10407 colonization.