RESUMO
A microbiological survival chamber for in situ environmental studies involving microorganisms of public health significance was developed. The autoclavable chamber was provided with a supportive base for proper flow orientation and a battery-powered stirring mechanism for continuous internal agitation. The performance of the chamber and its ancillary units was evaluated in estuarine waters by diffusion studies and survival tests with eight species of bacteria isolated from environmental sources. Polycarbonate filter membranes were found superior to cellulosic filter membranes. Continuous mixing enhanced diffusion and ensured uniform cell suspension. Salmonella enteritidis and Klebsiella pneumoniae exhibited somewhat greater viability than Escherichia coli under similar conditions. Of three indicator organisms tested, Streptococcus faecalis was the most persistent. In general, the data obtained indicate the usefulness of the chamber in measurements of microbial survival in the natural marine environment.
Assuntos
Bactérias/isolamento & purificação , Técnicas Bacteriológicas/instrumentação , Microbiologia da Água , Difusão , Enterobacter/isolamento & purificação , Enterococcus faecalis/isolamento & purificação , Escherichia coli/isolamento & purificação , Estudos de Avaliação como Assunto , Klebsiella pneumoniae/isolamento & purificação , Filtros Microporos , Pseudomonas aeruginosa/isolamento & purificação , Salmonella enteritidis/isolamento & purificação , Água do Mar , Staphylococcus aureus/isolamento & purificação , Temperatura , Vibrio parahaemolyticus/isolamento & purificaçãoRESUMO
The first reported isolations of halophilic vibrios, including Vibrio parahaemolyticus, from three seafood processing areas in Southeastern Alaska are described.
Assuntos
Resíduos Industriais , Microbiologia do Solo , Vibrio/isolamento & purificação , Microbiologia da Água , Alaska , Braquiúros , Temperatura Baixa , Decápodes , Produtos Pesqueiros , Indústria de Processamento de Alimentos , Água do Mar , Vibrio/crescimento & desenvolvimentoRESUMO
The ability of oysters to purge themselves of microbial contaminants was investigated by identifying the microorganisms retained by oysters after they have been subjected to ultraviolet (UV) light-treated seawater. A UV intensity of 960 muw per min per cm(2) reduced the microbial count of seawater from 263 to 13 per ml. The coliform multitube test (MPN) was reduced from a high of 17 to <0.18 per 100 ml. Over 75% of the microorganisms found in treated seawater were Acinetobacter/Moraxella, Vibrio/Pseudomonas type II, and Flavobacterium/Cytophaga. With the exception of coliforms, the microbial composition of oysters subjected to UV-treated seawater remained at levels comparable to the control oysters held in untreated seawater. Total counts ranged between 10(3) and 10(5)/g. The microorganism most frequently encountered were Flavobacterium/Cytophaga, Vibrio/Pseudomonas type II, Pseudomonas type III or IV, Acinetobacter/Moraxella, gram-positive cocci and Bacillus. Together they comprised over 90% of the flora. Coagulase-positive, deoxyribonuclease-positive, and beta-hemolytic cocci were found in some samples, as were V. parahaemolyticus, V. aliginolyticus, and Aeromonas species.
