RESUMO
We compared two PCR methods for molecular typing the medically important filamentous fungus Aspergillus terreus. In a set of 46 strains investigated we found 19 and 12 different fingerprinting types obtained by random amplified polymorphic DNA PCR (RAPD) and semi-automated repetitive element PCR (rep-PCR), respectively.
Assuntos
Aspergillus/classificação , Aspergillus/genética , Tipagem Molecular/métodos , Técnicas de Tipagem Micológica/métodos , Aspergilose/epidemiologia , Aspergilose/microbiologia , Aspergillus/isolamento & purificação , Impressões Digitais de DNA/métodos , DNA Fúngico/genética , Humanos , Sequências Repetitivas Dispersas , Epidemiologia Molecular/métodosRESUMO
Prospective studies addressing the clinical value of broad-range PCR using the internal transcribed spacer region (ITS) for diagnosis of microscopy-negative fungal infections in nonselected patient populations are lacking. We first assessed the diagnostic performance of ITS rRNA gene PCR compared with that of routine microscopic immunofluorescence examination. Second, we addressed prospectively the impact and clinical value of broad-range PCR for the diagnosis of infections using samples that tested negative by routine microscopy; the corresponding patients' data were evaluated by detailed medical record reviews. Results from 371 specimens showed a high concordance of >80% for broad-range PCR and routine conventional methods, indicating that the diagnostic performance of PCR for fungal infections is comparable to that of microscopy, which is currently considered part of the "gold standard." In this prospective study, 206 specimens with a negative result on routine microscopy were analyzed with PCR, and patients' clinical data were reviewed according to the criteria of the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group. We found that broad-range PCR showed a sensitivity, specificity, positive predictive value, and negative predictive value of 57.1%, 97.0%, 80%, and 91.7%, respectively, for microscopy-negative fungal infections. This study defines a possible helpful role of broad-range PCR for diagnosis of microscopy-negative fungal infections in conjunction with other tests.
Assuntos
Fungos/isolamento & purificação , Técnicas Microbiológicas/métodos , Micologia/métodos , Micoses/diagnóstico , Micoses/microbiologia , Reação em Cadeia da Polimerase/métodos , DNA Fúngico/genética , DNA Fúngico/isolamento & purificação , DNA Espaçador Ribossômico/genética , DNA Espaçador Ribossômico/isolamento & purificação , Fungos/classificação , Fungos/genética , Humanos , Valor Preditivo dos Testes , Estudos Prospectivos , Sensibilidade e EspecificidadeRESUMO
In contrast to infections with enterohaemorrhagic E. coli (EHEC), which are thought to be classical zoonosis, the zoonotic potential of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae is still widely unknown. The aim of our study was to determine the frequency of EHEC and ESBL-producing Enterobacteriaceae in domestic animals (dogs and cats) in the Tyrol. Among 228 fecal samples of dogs (n = 92) and cats (n = 136) three samples (1.3%) were positive in the EHEC-ELISA. In two of the three cases isolation of the organism was not possible, the third sample of a two-year-old crossbreed bitch yielded EHEC O103:H2. In twelve of 228 (5.3%) fecal samples 13 ESBL-producing Enterobacteriaceae (in ten cats and two dogs) were found.These animals mainly derived from homes for animals (ten animals, 83%). 75% of the isolates belonged to the CTX-M-1-group, 8% to the CTX-M-2-group and 17% to the CTX-M-9-group. One isolate was positive for CTX-M-1 and CTX-M-9. Typing of the 13 ESBL-producing isolates by multilocus sequence typing (MLST) showed ten different sequence types, which points out the importance of the horizontal transfer of mainly plasmid-coded ESBL genes. Transmission of EHEC and ESBL-producing Enterobacteriaceae from domestic animals to humans is possible, corroborated by the fact that the EHEC serotype found in one dog and the sequence types detected by MLST in several dogs and cats were previously reported to occur in severe human infection.
Assuntos
Doenças do Gato/microbiologia , Doenças do Cão/microbiologia , Escherichia coli Êntero-Hemorrágica/isolamento & purificação , Infecções por Escherichia coli/veterinária , Zoonoses/microbiologia , Animais , Antibacterianos/farmacologia , Áustria , Gatos , Cães , Escherichia coli Êntero-Hemorrágica/efeitos dos fármacos , Escherichia coli Êntero-Hemorrágica/enzimologia , Escherichia coli Êntero-Hemorrágica/genética , Infecções por Escherichia coli/microbiologia , Fezes/microbiologia , Feminino , Humanos , Testes de Sensibilidade Microbiana , Tipagem de Sequências MultilocusRESUMO
BACKGROUND: Community-acquired methicillin-resistant Staphylococcus aureus (caMRSA) is an emerging pathogen which causes potentially severe infections in young and healthy individuals due to the ability of most strains to produce Panton-Valentine leukocidin (PVL). The aim of this study was to evaluate the prevalence of PVL-positive (PVL(+))-MRSA strains in Western Austria in the period from December 2005 to May 2010 and to characterize the identified PVL(+)-MRSA strains. METHODS: Six hundred and fifty MRSA strains from Innsbruck Medical University hospital, district hospitals, and general practitioners were investigated for the presence of lukS-lukF gene (encoding for PVL). Antimicrobial resistance testing, SCCmec-, agr-, MLST- and spa-typing, as well as arcA determination were performed on PVL(+)-MRSA. RESULTS: Among 650 MRSA strains collected from various body sites from hospitalized patients and outpatients, 31 strains (4.8 %) were positive for lukS-lukF and thus identified as PVL(+)-MRSA. Agr-1 was the most common agr-type (n = 18, 58.1 %) and SCCmec-IV or variants IVa and IVc were the most common SCCmec types (n = 27, 87.1 %). All tested strains showed in-vitro susceptibility to vancomycin and rifampicin, but resistance against cotrimoxazol (6.4 %), clindamycin (9.7 %), gentamicin (9.7 %), fusidic acid (12.9 %), levofloxacin (12.9 %), and erythromycin (61.3 %) was found. Most lukS-lukF-positive MRSA detected in our survey shared ST8 and t008 and were positive for arcA. CONCLUSIONS: The major lukS-lukF-positive MRSA lineage found in our population was ST8, t008 and positive for arcA which is mainly found in the USA. In contrast, ST80 strains were not found as frequently in our region as in many other European countries.
Assuntos
Toxinas Bacterianas/biossíntese , Exotoxinas/biossíntese , Leucocidinas/biossíntese , Resistência a Meticilina/genética , Infecções Estafilocócicas/genética , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Staphylococcus aureus/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Áustria , Toxinas Bacterianas/genética , Criança , Exotoxinas/genética , Feminino , Humanos , Leucocidinas/genética , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Azole resistance in Aspergillus terreus isolates was explored. Twenty related (MB) and 6 unrelated A. terreus isolates were included. CYP51A sequencing and RAPD genotyping was performed. Five MB isolates were itraconazole susceptible, whereas the minimum inhibitory concentrations (MICs) for 15 MB isolates were elevated (1-2 mg/L). Voriconazole and posaconazole MICs were 0.5-4 and 0.06-0.5 mg/L, respectively, for MB isolates but 0.25-0.5 and <0.03-0.06 mg/L, respectively, for controls. Sequencing identified a Cyp51Ap M217I alteration in all 15 isolates with elevated itraconazole MICs. Genotyping showed that 18 of 20 MB isolates were identical and unique, suggesting endogenous origin. In conclusion, itraconazole resistance in A. terreus was linked to an M217I Cyp51A alteration.
Assuntos
Antifúngicos/farmacologia , Aspergillus/classificação , Aspergillus/efeitos dos fármacos , Azóis/farmacologia , Sistema Enzimático do Citocromo P-450/metabolismo , Farmacorresistência Fúngica Múltipla/genética , Proteínas Fúngicas/metabolismo , Sistema Enzimático do Citocromo P-450/genética , DNA Fúngico/genética , Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Genótipo , Humanos , Itraconazol/farmacologia , Testes de Sensibilidade Microbiana , MutaçãoRESUMO
Rapid detection of bloodstream infections is an important issue for a better patient outcome. The aim of our study was thus to evaluate the LightCycler SeptiFast assay for diagnosis of bloodstream pathogens in a tertiary hospital in Western Austria. The 71 blood samples of 61 patients with presumed sepsis were investigated and compared with conventional blood culture system results. In both assays, 51 samples (71.8 %) were negative. In 20 positive samples (28.2 %), 10 different pathogens were detected by either blood culture system or SeptiFast assay or by both methods. Five samples were positive in both assays. The agreement rate of blood culture system and SeptiFast assay was 78.9 %, the negative predictive value of SeptiFast assay versus blood culture system was 0.94, sensitivity was 0.63, and specificity 0.81. In 12 samples where a positive SeptiFast assay and a negative blood culture system result were obtained, the same pathogens as identified by SeptiFast assay were detected in samples from other body sites suggesting a correct positive detection. In 11.3 % of cases, the SeptiFast assay resulted in an adjustment of the patients' therapy. In 3 samples, the blood culture assay was positive whereas the SeptiFast assay yielded negative results. In two of these cases, the pathogens involved were not included in the SeptiFast detection list, in the third case SeptiFast assay failed to detect Candida glabrata.Thus we recommend the SeptiFast assay as a valuable tool for rapid diagnosis of bloodstream infections in addition to, but not as replacement for, the blood culture test.
Assuntos
Bacteriemia/sangue , Bacteriemia/microbiologia , Bactérias/genética , Bactérias/isolamento & purificação , Patógenos Transmitidos pelo Sangue/isolamento & purificação , Técnicas Microbiológicas/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Bacteriemia/diagnóstico , Bactérias/classificação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
The rapid emergence and dissemination of carbapenemase-producing Enterobacter species and other members of the Enterobacteriaceae poses a considerable threat to the care of hospitalized patients and to public health. In this study, Enterobacter isolates demonstrating decreased susceptibility to carbapenems detected at the Division of Hygiene and Medical Microbiology, Innsbruck Medical University, between January 2006 and December 2010 were tested for bla(VIM-1), bla(NDM-1), bla(IMP), bla(KPC) and bla(OXA-48) using a multiplex PCR with published primers. PFGE was performed to determine the genetic relatedness. In total, 33 isolates (28 Enterobacter cloacae and 5 Enterobacter aerogenes) were collected during the study period. From 2006 to 2009, between two and seven isolates were found per year. In 2010, a significant increase of carbapenem-resistant strains was observed (nâ=â12). The bla(VIM-1) gene was detected in all 28 isolates of E. cloacae. Typing of E. cloacae by PFGE revealed three distinct clusters, the biggest of which contained 18 isolates. These findings demonstrate the emergence of VIM-1-producing Enterobacter in Tyrol, western Austria. The clonal relationship confirms the risk of spread of these organisms and their possible persistence over time.
Assuntos
Proteínas de Bactérias/metabolismo , Carbapenêmicos/farmacologia , Enterobacter cloacae/efeitos dos fármacos , Enterobacter cloacae/enzimologia , Infecções por Enterobacteriaceae/microbiologia , beta-Lactamases/metabolismo , Antibacterianos/farmacologia , Áustria/epidemiologia , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana Múltipla , Eletroforese em Gel de Campo Pulsado , Enterobacter cloacae/genética , Infecções por Enterobacteriaceae/epidemiologia , Humanos , Testes de Sensibilidade Microbiana , beta-Lactamases/genéticaRESUMO
BACKGROUND: Candida krusei (Ck) may cause severe infections in immunocompromised hosts and is innately resistant to fluconazole. PATIENTS AND METHODS: During an 18-month period, seven patients with Ck infection were identified at our center. All were treated in the transplant intensive care unit. Candida isolates were grown on Sabouraud agar, and chromosomal DNA was extracted; clonality was investigated using random amplified polymorphic DNA-polymerase chain reaction with primers M13, OPA-18, and OPE-18. RESULTS: Among the patients with Ck infection, there were three pancreas recipients with intra-abdominal infection, one liver recipient with cholangitis, one lung recipient with pleural empyema, one patient with pleural empyema after esophageal perforation, and one case of pneumonia in a patient with a ventricular assist device. Treatment consisted of caspofungin (n = 3), voriconazole (n = 1), or a combination of the two (n = 2) together with surgery (n = 3) or pigtail catheter drainage (n = 3). One patient underwent drainage without antifungal treatment, and one patient did not have drainage. The infection was controlled in all cases. The patient with the assist device died from multiple organ dysfunction, the lung recipient died after four months from graft failure, and one pancreas graft was lost. Four patients (57%) harbored the same Ck strain. CONCLUSION: Solid organ recipients seem to be at particular risk for Ck infections; clonal outbreaks may occur in intensive care units.
Assuntos
Candida/classificação , Candida/isolamento & purificação , Candidíase/microbiologia , Infecção Hospitalar/microbiologia , Transplante de Órgãos/efeitos adversos , Complicações Pós-Operatórias/microbiologia , Adulto , Idoso , Antifúngicos/uso terapêutico , Candidíase/epidemiologia , Caspofungina , Análise por Conglomerados , Infecção Hospitalar/epidemiologia , Impressões Digitais de DNA , DNA Fúngico/genética , Equinocandinas/uso terapêutico , Feminino , Genótipo , Humanos , Hospedeiro Imunocomprometido , Lipopeptídeos , Masculino , Pessoa de Meia-Idade , Técnicas de Tipagem Micológica/métodos , Pirimidinas/uso terapêutico , Técnica de Amplificação ao Acaso de DNA Polimórfico , Resultado do Tratamento , Triazóis/uso terapêutico , VoriconazolRESUMO
Infections with enterohemorrhagic Escherichia coli (EHEC) are a major cause of hemolytic uremic syndrome (HUS). Shiga toxins (Stxs), especially Stx2, are believed to represent major virulence factors of EHEC, contributing to HUS pathogenesis. Beside EHEC-associated HUS, there are hereditary atypical forms of HUS, which are mostly caused by mutations of complement regulators. The aim of the present study was to investigate whether or not complement is also involved in the pathogenesis of EHEC-induced typical HUS, by being activated either directly or indirectly by involvement of its inhibitors. Purified Stx2 markedly activated complement via the alternative pathway and was found to bind to factor H (FH), however, only when it was active. No apparent cleavage or destruction of FH was visible, and cofactor activity in fluid phase was unaffected, but clearly delayed for surface-attached FH, where it is essential for host cell protection. Binding studies using FH constructs revealed that Stx2 binds to short consensus repeats (SCRs) 6-8 and SCRs18-20, but not to SCRs16-17, i.e., to regions involved in the surface recognition function of FH. In conclusion, complement, and in particular FH, not only plays an important role in atypical HUS, but most probably also in EHEC-induced HUS.
Assuntos
Ativação do Complemento/fisiologia , Fator H do Complemento/metabolismo , Síndrome Hemolítico-Urêmica/metabolismo , Toxina Shiga/metabolismo , Animais , Western Blotting , Células CHO , Cricetinae , Cricetulus , Escherichia coli Êntero-Hemorrágica , Ensaio de Imunoadsorção Enzimática , Infecções por Escherichia coli/complicações , Síndrome Hemolítico-Urêmica/microbiologia , Humanos , ImunoprecipitaçãoRESUMO
Infections with enterohemorrhagic Escherichia coli (EHEC) are the major cause of hemolytic uremic syndrome (HUS), the most common cause of acute renal failure in childhood. Shiga toxins are considered to be the most important virulence factor of EHEC strains. Non-sorbitol-fermenting EHEC O157:H7 is still the most prevalent serotype isolated worldwide; however, sorbitol-fermenting (SF) EHEC O157:H- (H- indicates nonmotility) strains are increasingly reported. Thirteen SF EHEC O157:H- strains (11 of human origin, two from animals) were detected in Austria between 2002 and 2008. Among the 11 human cases, seven suffered from HUS, two from diarrhea and the remaining two were asymptomatic. Seven of the cases were identified in patients living in or visiting (in one case) the province Salzburg, four were in patients from the province Vorarlberg. Three outbreaks with no more than three persons involved were detected, the other four cases occurred sporadically. The pulsed-field gel-electrophoresis banding patterns of the 13 SF EHEC O157:H- isolates were grouped into three distinct clusters (groups 1, 2 and 3). Strains of the three outbreaks were identical (except for one outbreak strain with one band difference) within each outbreak. In comparison, the Bavarian epidemic strain showed a pattern different from all SF O157:H- strains isolated in Austria. For effective detection of SF EHEC O157:H-, screening for Shiga toxins by ELISA and/or Shiga toxin genes by PCR is absolutely necessary; screening on the basis of phenotypic characteristics such as sorbitol-non-fermentation is not sufficient. Typing methods relying solely on investigation of O157 will detect these strains but should nevertheless also be avoided, so that the prevalent non-O157 strains causing HUS are not missed.
Assuntos
Diarreia/microbiologia , Surtos de Doenças , Infecções por Escherichia coli/microbiologia , Escherichia coli O157/patogenicidade , Doenças Transmitidas por Alimentos/microbiologia , Gastroenterite/microbiologia , Síndrome Hemolítico-Urêmica/microbiologia , Escherichia coli Shiga Toxigênica/patogenicidade , Sorbitol/metabolismo , Animais , Áustria , Bovinos/microbiologia , Pré-Escolar , Análise por Conglomerados , Busca de Comunicante , Diarreia/epidemiologia , Surtos de Doenças/estatística & dados numéricos , Reservatórios de Doenças , Eletroforese em Gel de Campo Pulsado , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/transmissão , Escherichia coli O157/classificação , Escherichia coli O157/genética , Fezes/microbiologia , Feminino , Fermentação , Doenças Transmitidas por Alimentos/epidemiologia , Gastroenterite/epidemiologia , Genótipo , Síndrome Hemolítico-Urêmica/epidemiologia , Humanos , Lactente , Masculino , Fenótipo , Toxina Shiga , Escherichia coli Shiga Toxigênica/classificação , Escherichia coli Shiga Toxigênica/genética , Virulência/genéticaRESUMO
Besides Shiga toxins (Stx), Stx-producing Escherichia coli (STEC) harbour several other putative virulence factors, including the serine protease EspP. We have investigated 214 STEC strains from Austria belonging to 61 different serotypes from humans, animals, and food for the presence of this serine protease gene and have determined the espP subtypes and their association with clinical outcome. espP was detected in 121 (57%) out of 214 strains. Sixty-five of 68 strains (96%) of non-sorbitol-fermenting (NSF) O157:H7/NM (NM, non-motile) were positive for espP, while none of 8 SF E. coli O157:NM isolates contained this gene. All 9 strains of serotype O145:NM and 17 of 21 strains (81%) of serotype O26:H11/NM were positive for espP. Nineteen STEC serogroups including O103 and O111 serogroups--considered to be highly pathogenic--were completely negative for espP. Only 5 of 12 strains isolated from patients suffering from haemolytic uraemic syndrome (HUS) were espP-positive (all serogroup NSF O157) as well as 28 of 39 strains from patients with bloody diarrhoea, 40 of 63 strains from patients with non-bloody diarrhoea, and 15 of 19 strains from asymptomatic patients. In O157:H7/NM, O26:H11/NM, and O145:NM only espP subtype alpha was found, whereas in most of the other non-O157 serogroups, subtypes beta and gamma were found. Subtype delta was not detected in our strain collection. Regarding the espP subtypes, only subtype alpha, but not beta and gamma, were found in HUS patients. Moreover, we could demonstrate that espP, and in particular subtype alpha, is associated with highly pathogenic serogroups.
Assuntos
Proteínas de Escherichia coli/genética , Serina Endopeptidases/genética , Escherichia coli Shiga Toxigênica/enzimologia , Escherichia coli Shiga Toxigênica/patogenicidade , Fatores de Virulência/genética , Animais , Áustria , DNA Bacteriano/genética , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Microbiologia de Alimentos , Genótipo , Humanos , Reação em Cadeia da Polimerase/métodos , Sorotipagem , Escherichia coli Shiga Toxigênica/classificação , Escherichia coli Shiga Toxigênica/genética , Escherichia coli Shiga Toxigênica/isolamento & purificaçãoRESUMO
The study investigated tetracycline (TC), ampicillin (AMP), cefazolin (CEF), and trimethoprim (TMP) resistance in Escherichia coli (E. coli) in the feces of 21 infants up to 6 months of age and in their parents in the absence of selective antimicrobial pressure. Clonality of strains was assessed by pulsed-field gel electrophoresis. Three infants had resistant E. coli strains in their feces identical to the mothers' from week 1 on, which persisted over weeks. From week 2 on, in another four infants, persisting resistant E. coli were found, two of them identical to the mothers'. All of these persisting E. coli strains (except one family) showed at least resistance to TC. In infants, resistant E. coli strains inherited from their mothers tended to persist over months. Therefore, the persistence of resistant E. coli and their possible capacity to cause symptomatic infection or transfer its resistance genes to other bacteria deserves more attention.
Assuntos
Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Intestinos/microbiologia , Mães , Resistência a Tetraciclina , Tetraciclina/farmacologia , Ampicilina/farmacologia , Cefazolina/farmacologia , Farmacorresistência Bacteriana , Eletroforese em Gel de Campo Pulsado , Fezes/microbiologia , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Testes de Sensibilidade Microbiana , Trimetoprima/farmacologiaRESUMO
The prevalence of Listeria monocytogenes in different types of produce and on processing plant environments was investigated over a 4-year period in a large produce processing plant in Poland. Prevalence of L. monocytogenes was 46% in frozen vegetables and 41.3% in swab samples taken from the plant environment. Survival studies using artificial inocula demonstrated that the number of Listeria in frozen produce stored for 100 days did not significantly decrease in relation to the initial contamination level. A subset of 129 L. monocytogenes isolates originating from produce and the plant environment were typed by pulsed-field gel electrophoresis. Seventy-six of these isolates were retyped by ribo- and serotyping. Thirteen pulsotypes and 18 ribotypes were distinguished. Persistent Listeria isolates were found even when cleansing and sanitization was applied on a daily basis. Nine (69.2%) of 13 pulsotypes were recovered during a period of more than 2 years. L. monocytogenes of the same pulsotype was isolated from broccoli sampled directly before and after blanching, thus suggesting that blanching at 92 to 95 degrees C for 4 to 8 min did not result in a Listeria-free product, most likely due to massive recontamination. This finding is of importance since blanching is the only critical control point in produce processing. Cross-contamination between the two lines was demonstrated through isolating L. monocytogenes strains indistinguishable by pulsed-field gel electrophoresis from contaminated gloves and floor surfaces.
Assuntos
Contaminação de Alimentos/análise , Manipulação de Alimentos/métodos , Indústria de Processamento de Alimentos/normas , Listeria monocytogenes/crescimento & desenvolvimento , Verduras/microbiologia , Técnicas de Tipagem Bacteriana , Contagem de Colônia Microbiana , Eletroforese em Gel de Campo Pulsado/métodos , Microbiologia de Alimentos , Genótipo , Humanos , Higiene , Polônia , Prevalência , SorotipagemRESUMO
Infections with enterohemorrhagic Escherichia coli (EHEC) result in various clinical symptoms and outcomes ranging from watery or bloody diarrhea to the life-threatening hemolytic-uremic syndrome (HUS). Shiga toxins (Stxs) are supposed to play a major role in the pathogenesis of EHEC infections; however, the role of other putative virulence factors is not fully elucidated. So far, there is only supportive therapy available for the treatment of both EHEC-associated diarrhea and HUS. Antibiotic therapy for the treatment of EHEC-associated diarrhea is discussed. In recent years other therapeutic strategies have been developed, including Gb3 receptor analogues, that bind Stx in the gut or in the circulation, passive immunization with Stx-neutralizing monoclonal antibodies, or active immunization with Stx1 And Stx2 toxoids as a preventive procedure. These approaches have been demonstrated to be effective in animal models but clinical trials are lacking.
Assuntos
Escherichia coli Êntero-Hemorrágica/efeitos dos fármacos , Infecções por Escherichia coli/prevenção & controle , Animais , Anticorpos Monoclonais/farmacologia , Anticorpos Monoclonais/uso terapêutico , Escherichia coli Êntero-Hemorrágica/isolamento & purificação , Infecções por Escherichia coli/tratamento farmacológico , Humanos , Toxinas Shiga/isolamento & purificação , Resultado do TratamentoRESUMO
Literature harbours several reports of potable water-associated outbreaks. We studied the prevalence of Shiga toxin- (stx1/2), intimin- (eae) and haemolysin (hlyA) genes in Escherichia coli isolates from drinking water of private and public water supplies in a rural area of Upper Austria; 2633 water samples were gained between November 2000 and December 2003. Two hundred and eighty of these water samples were positive for E. coli (10.6%). Of these, 101 samples were drawn from drilled wells (36%), 96 from dug wells (34%), 61 from springs (22%) and 22 from water supplies without available information on technical details (8%); 141 of the samples were from public water supplies, 139 from private water supplies. Eleven of the E. coli isolates were found to be positive for one of the investigated virulence genes (3.9%): one isolate yielded stx2, seven eae, and three isolates had hlyA. The presence of these genes underlines the importance of control of water quality in public and also private water supplies.
Assuntos
Adesinas Bacterianas/isolamento & purificação , Escherichia coli Enteropatogênica/genética , Proteínas de Escherichia coli/isolamento & purificação , Proteínas Hemolisinas/isolamento & purificação , Toxina Shiga I/isolamento & purificação , Toxina Shiga II/isolamento & purificação , Microbiologia da Água , Abastecimento de Água/análise , Adesinas Bacterianas/genética , Áustria , Ingestão de Líquidos , Eletroforese em Gel de Campo Pulsado , Escherichia coli Enteropatogênica/isolamento & purificação , Escherichia coli O157/genética , Proteínas de Escherichia coli/genética , Proteínas Hemolisinas/genética , Humanos , Reação em Cadeia da Polimerase , Prevalência , Estudos Prospectivos , População Rural , Toxina Shiga I/genética , Toxina Shiga II/genética , Escherichia coli Shiga Toxigênica/genética , Escherichia coli Shiga Toxigênica/isolamento & purificaçãoRESUMO
Shiga toxins (Stx) are believed to play a key role in the pathogenesis of diseases caused by Stx-producing Escherichia coli (STEC), including the potentially life-threatening hemolytic uremic syndrome (HUS). In this study, 201 STEC strains collected from patients and environmental sources were investigated with regard to the stx genotypes and pathogenicity. The stx(2) and stx(2c) alleles were associated with high virulence and the ability to cause HUS, whereas stx(2d), stx(2e,)stx(1), and stx(1c) occurred in milder or asymptomatic infections. Quantification of Stx using an enzyme immunoassay and the Vero cell cytotoxicity assay showed no significant differences between the strains associated with HUS and those causing milder diseases. We hypothesize that the stx genotype and perhaps other yet unknown virulence factors rather than the amount of Stx or the in vitro cytotoxicity correlate with the development of HUS.
Assuntos
Síndrome Hemolítico-Urêmica/microbiologia , Toxina Shiga I/genética , Toxina Shiga II/genética , Escherichia coli Shiga Toxigênica/genética , Adesinas Bacterianas/metabolismo , Animais , Chlorocebus aethiops , Proteínas de Escherichia coli/metabolismo , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos , Genótipo , Humanos , Técnicas Imunoenzimáticas , Toxina Shiga I/classificação , Toxina Shiga II/classificação , Escherichia coli Shiga Toxigênica/classificação , Escherichia coli Shiga Toxigênica/patogenicidade , Células Vero/microbiologia , Virulência/genéticaRESUMO
Aspergillus terreus isolates collected from patients at The M. D. Anderson Cancer Center in Houston, TX, and at The University Hospital of Innsbruck, Austria, were analyzed using random amplification of polymorphic DNA-PCR with three different primers. No strain similarity in either institution was detected, indicating great genetic diversity of A. terreus.
Assuntos
Aspergilose/microbiologia , Aspergillus/classificação , Aspergillus/isolamento & purificação , Polimorfismo Genético , Aspergillus/genética , Áustria , Análise por Conglomerados , Impressões Digitais de DNA , DNA Fúngico/genética , Humanos , Técnica de Amplificação ao Acaso de DNA Polimórfico , TexasRESUMO
Rapid detection of enterohemorrhagic Escherichia coli is important for its successful treatment. We have evaluated the immunochromatographic Duopath Verotoxin-test for detection of Shiga toxins, in comparison with enzyme-linked immunosorbent assay and polymerase chain reaction, on 240 clinical human stool samples. The Duopath-test showed a lower sensitivity and specificity.
Assuntos
Infecções por Escherichia coli/diagnóstico , Fezes/microbiologia , Imunoensaio/métodos , Toxinas Shiga/análise , Cromatografia/métodos , Ensaio de Imunoadsorção Enzimática , Humanos , Reação em Cadeia da Polimerase , Valor Preditivo dos TestesRESUMO
Tellurite-containing media are widely used for the screening and isolation of Shiga toxin-producing Escherichia coli (STEC) O157:H7, but tellurite resistance among non-O157 STEC is poorly characterized. Therefore, we investigated 202 STEC strains representing 61 different serotypes from humans, animals or food for the presence of ter genes by PCR and their correlation with tellurite resistance, by assessing growth on cefixime-tellurite sorbitol MacConkey agar. All strains were screened for terC, terE and terF as markers for the ter gene cluster. Of the 202 strains, 127 contained terC and terE and were tellurite-resistant, but only 121 of these also contained terF. All 72 non-sorbitol-fermenting O157:H7 and O157:NM (non-motile) strains contained terC, terE and terF and expressed tellurite resistance. In contrast, all eight sorbitol-fermenting STEC O157:NM were terC-, terE- and terF-negative and tellurite-sensitive. Among non-O157 STEC, terC, terE and terF were found in all seven O145:NM, four O111:H8/NM, 17 of 18 O26:H11/NM and in 21 strains of 14 other serotypes. The strong correlation between the presence of ter genes and the ability to grow on tellurite-containing media suggest that the ter genes encode tellurite resistance in the vast majority of these strains. The presence of the ter gene cluster was significantly (P<0.00001) associated with the presence of eae genes. We conclude that the use of tellurite-containing media in screening for STEC will allow the detection of STEC O26, O111, O145 and non-sorbitol-fermenting O157, but most strains (in this study 74.3%) from other serotypes will be missed.
Assuntos
Proteínas de Ligação a DNA/genética , Farmacorresistência Bacteriana/genética , Infecções por Escherichia coli/microbiologia , Escherichia coli O157/efeitos dos fármacos , Escherichia coli O157/genética , Proteínas de Escherichia coli/genética , Síndrome Hemolítico-Urêmica/microbiologia , Telúrio/farmacologia , Adesinas Bacterianas/genética , Animais , Bovinos , Cefixima , Meios de Cultura , Escherichia coli O157/crescimento & desenvolvimento , Microbiologia de Alimentos , Genes Bacterianos , Cabras , Humanos , Carne/microbiologia , Leite/microbiologia , Família Multigênica , Toxina Shiga/metabolismoRESUMO
Novel and as yet rare non-O157 Shiga toxin (Stx)-producing Escherichia coli (STEC) serotypes are emerging in Europe. Two different sorbitol-fermenting STECs, O100:H- carrying the virulence gene stx2 and O127:H40 carrying stx1 and eae genes (found in two related subjects), were isolated from patients' stool samples. Non-O157 STEC infections in humans are currently under-diagnosed. This report highlights the need for, and importance of, screening for Shiga toxins or serotypes other than just O157.