RESUMEN
AIMS: An assessment of microbial densities in an urbanized Florida watershed was performed during a period of changing rainfall patterns to investigate the role of climate coupled with urbanization in declining water quality. METHODS AND RESULTS: Concentrations of traditional and alternative faecal indicators were assessed by standard methods over 24 months. Sources of faecal contamination were determined by antibiotic resistance analysis (ARA) of faecal coliform (FC) bacteria. Composite indices of indicator organisms based on a suite of microbial measurements were used to quantify pollution impacts in the river. ARA results found that FC from wild animal sources dominated during the drought, and the relative frequency of FC from human sources increased after cumulative rainfall increased to near-normal levels. CONCLUSIONS: Changes observed in faecal indicator densities and in FC sources during changing rainfall patterns strongly suggest a role of precipitation on the sources and extent of microbial pollution in urbanized coastal watersheds. SIGNIFICANCE AND IMPACT OF THE STUDY: Bacterial source tracking coupled with a composite index of microbial contamination resulted in a more complete picture of microbial pollution within the river, as opposed to the general practice of reliance on one indicator organism. Improved land use decisions in urban areas are necessary to insure maintenance of coastal environmental health under changing climate patterns and population density.
Asunto(s)
Monitoreo del Ambiente/métodos , Heces/microbiología , Lluvia , Estaciones del Año , Microbiología del Agua , Contaminación del Agua , Animales , Animales Salvajes , Técnicas de Tipificación Bacteriana , Humanos , Ríos , Agua de Mar , Estados Unidos , UrbanizaciónRESUMEN
AIMS: The genus Enterococcus includes opportunistic pathogens such as E. faecalis and E. faecium, and is also used to assess water quality. Speciation of enterococci in environmental studies can be particularly problematic, therefore protocols for unambiguous, DNA-based analysis could receive wide use in applications ranging from water quality monitoring to microbial source tracking. The goal of this work was to investigate the usefulness of PCR for speciation of putative, biochemically identified E. faecalis and E. faecium isolated from water, faeces and sewage. METHODS AND RESULTS: Putative enterococci (n = 139) were isolated on mEI agar from dog, human, gull and cow faeces, and from sewage, freshwaters and marine waters. A total of 128 isolates passed standard physiological tests for the genus, and were speciated by the API 20 Strep (APIStrep) biochemical test system. 42.2% were identified as E. faecalis, and all were confirmed by PCR. 19.5% were biochemically identified as E. faecium, but only seven were PCR-positive. CONCLUSIONS: The 16S rDNA of PCR-positive and PCR-negative E. faecium, including isolates that were inconclusively identified by APIStrep, was sequenced. All formed a monophyletic clade with E. faecium sequences in Genbank. SIGNIFICANCE AND IMPACT OF THE STUDY: Biochemical identification of E. faecalis agreed 100% with PCR assays, therefore a simple protocol of isolation on mEI followed by PCR should be useful for environmental studies. Discrepancies among biochemical identification, PCR confirmation and DNA sequencing were noted for E. faecium, indicating that routine isolation/identification of E. faecium from environmental samples is a much more difficult task.
Asunto(s)
Técnicas de Tipificación Bacteriana , Enterococcus faecalis/clasificación , Enterococcus faecalis/genética , Enterococcus faecium/clasificación , Enterococcus faecium/genética , Reacción en Cadena de la Polimerasa/métodos , Canal Anal/microbiología , Animales , ADN Bacteriano/análisis , ADN Bacteriano/química , ADN Bacteriano/aislamiento & purificación , ADN Ribosómico/química , ADN Ribosómico/aislamiento & purificación , Enterococcus faecalis/aislamiento & purificación , Enterococcus faecium/aislamiento & purificación , Heces/microbiología , Agua Dulce/microbiología , Genes de ARNr/genética , Humanos , Filogenia , ARN Ribosómico 16S/genética , Agua de Mar/microbiología , Análisis de Secuencia de ADN , Homología de Secuencia de Ácido Nucleico , Aguas del Alcantarillado/microbiología , Microbiología del AguaRESUMEN
Vancomycin-resistant Enterococcus spp. (VRE) were isolated from sewage and chicken feces but not from other animal fecal sources (dog, cow, and pig) or from surface waters tested. VRE from hospital wastewater were resistant to > or =20 microg of vancomycin/ml and possessed the vanA gene. VRE from residential wastewater and chicken feces were resistant to 3 to 5 microg of vancomycin/ml and possessed the vanC gene.
Asunto(s)
Pollos/microbiología , Enterococcus/efectos de los fármacos , Enterococcus/aislamiento & purificación , Heces/microbiología , Aguas del Alcantarillado/microbiología , Resistencia a la Vancomicina , Animales , Antibacterianos/farmacología , Bovinos , Perros , Humanos , Pruebas de Sensibilidad Microbiana , Estados Unidos , Resistencia a la Vancomicina/genética , Microbiología del AguaRESUMEN
Human monocytic ehrlichiosis is an emerging zoonosis caused by infection with Ehrlichia chaffeensis Anderson, Dawson, Jones & Wilson, which is transmitted to mammals by ixodid ticks. Prevalence of infected ticks and distribution of infection foci indicate relative risk of human exposure to ehrlichiosis and may be influenced by factors such as geographic isolation, human disturbance, and the availability of suitable mammalian reservoir hosts. To test, this, individual and pooled lone star ticks, Amblyomma americanum (L.), were collected from three populations from the Georgia coast (1 mainland site and two barrier islands) and screened for E. chaffeensis. A species-specific, nested polymerase chain reaction (PCR) assay was used to amplify a 572 bp fragment of the E. chaffeensis 16S rRNA gene from infected ticks. PCR product specificity was confirmed by nucleotide sequencing. Our results showed the prevalence of infected ticks to be 0.0% (n = 151), 0.9% (n = 111), and 9.3% (n = 129) for Sapelo Island, St. Catherine's Island, and Fort McAllister, respectively.
Asunto(s)
Ehrlichia chaffeensis/aislamiento & purificación , Garrapatas/microbiología , Animales , Geografía , Georgia , Cómputos Matemáticos , Reacción en Cadena de la Polimerasa/métodos , Prevalencia , ARN Bacteriano/análisis , ARN Ribosómico 16S/análisis , Análisis de Secuencia de ARNRESUMEN
The anaesthetic management of a patient with haemoglobin SC disease for lower segment Caesarean section and excision of a phaeochromocytoma is described. The patient was given a general anaesthetic for the surgical procedure after exchange transfusion had achieved an haemoglobin A concentration of greater than 50%. A live infant was delivered and a suprarenal phaeochromocytoma was excised during a 6.5 hour procedure. The patient's postoperative recovery was uneventful.