Search results for "Enterobacter"
showing 10 items of 183 documents
Microbial contamination of milk and dairy products from restaurants in Spain
2009
This study was carried out to evaluate the microbiological quality of milk and some dairy products, including 95 lots of warm milk, 95 lots of milk conserved at room temperature, and 75 lots of dairy products collected from restaurants in Spain. According to the European microbiological criteria (92/46/EEC, 93/43/EEC, and Commission Regulation No. 2073/2005), 31% and 35% of the total examined lots exceed the adopted limits of mesophilic aerobic counts and Enterobacteriaceae, respectively. This may be due to incorrect handling of milk and dairy products and inadequate cleaning and sanitization of milk container. Further, 2% of all the lots examined were positive for the presence of Escherich…
Microbial evaluation of Spanish potato omelette and cooked meat samples in University restaurants.
2000
The focus of this study was to evaluate the microbial quality of Spanish potato omelette and cooked meat samples including pork loin, chicken croquettes, long pork sausage, chicken breast, and meatballs from University restaurants. Microbiological analyses of Spanish potato omelette and cooked meat samples resulted in aerobic plate counts from1.00 to 2.90 and from1.00 to 6.04 log10 CFU g(-1), respectively. Total coliforms ranged from3 to 43 most probable number (MPN) g(-1) and from3 to2,400 MPN g(-1) for Spanish potato omelette and meat products, respectively. Escherichia coli, coagulase-positive staphylococci, and Lancefield group-D streptococci were detected in 1.7%, 3.5%, and 12.9% of Sp…
Siderophore production by environmental strains ofSalmonellaspecies
1989
Iron uptake mechanisms were investigated in different species of Salmonella isolated from environmental waters. All strains examined were able to grow in the presence of high concentrations (10 mM) of the iron chelator EDDA. All strains excreted phenolate and hydroxamate siderophores, as assessed by bioassays and chemical tests. Bioassays with different indicator strains showed that all Salmonella strains can cross-feed other Enterobacteria, as well as mutants of Salmonella typhimurium deficient in the Enterobactin system, suggesting that this siderophore may be produced by the environmental Salmonella strains. The siderophore aerobactin may also be produced by one of the strains, according…
Assessment of the microbiological quality and wash treatments of lettuce served in University restaurants
2000
Abstract One hundred and forty-four samples of lettuce from 16 University restaurants were analyzed. The mesophilic aerobic counts of all samples ranged from 3.01 to 7.81 log 10 CFU g −1 . Results of total coliforms ranged from 3.38 log 10 most probable number (MPN) g −1 . Of the lettuce samples, 25.7% harbored Escherichia coli , 22.9% Staphylococcus aureus and 84% group D streptococci. Similarly, 10.4% of the samples harbored Aeromonas hydrophila , 2.8% Pseudomonas aeruginosa , and coliforms such as 14.6% Citrobacter freundii , 8.3% Klebsiella pneumoniae , 4.2% Enterobacter cloacae and 1.4% Providencia spp. Salmonella , Shigella and E. coli O157:H7 were not detected. When sodium hypochlori…
A single method for recovery and concentration of enteric viruses and bacteria from fresh-cut vegetables
2011
Fresh-cut vegetables are prone to be contaminated with foodborne pathogens during growth, harvest, transport and further processing and handling. As most of these products are generally eaten raw or mildly treated, there is an increase in the number of outbreaks caused by viruses and bacteria associated with fresh vegetables. Foodborne pathogens are usually present at very low levels and have to be concentrated (i.e. viruses) or enriched (i.e. bacteria) to enhance their detection. With this aim, a rapid concentration method has been developed for the simultaneous recovery of hepatitis A virus (HAV), norovirus (NV), murine norovirus (MNV) as a surrogate for NV, Escherichia coli O157:H7, List…
Improved acid tolerance of a recombinant strain of Escherichia coli expressing genes from the acidophilic bacterium Oenococcus oeni.
2001
Aims:Oenococcus oeni is a lactic acid bacterium used in wine fermentation. Two open reading frames (orfB and orfC) were identified in the upstream region of the hsp18 gene, encoding the small heat-shock protein Lo18. Expression of these genes in conditions of acid stress was studied in Escherichia coli. Methods and Results: Sequence analysis showed that orfB encodes a putative transcriptional regulator of the LysR family. The protein encoded by orfC shares homologies with multi-drug resistance systems. Heterologous expression of orfB, orfC and hsp18 genes in Escherichia coli significantly enhanced the viability of the host strain under acidic conditions. Conclusions: It was demonstrated tha…
Salmonella serovars identified at the centre for enterobacteriaceae of palermo over the 5-year period 1983-87
1990
Salmonellosis is become an increasing public health problem in many countries. Serotyping and assessment of antibiotic resistance are useful tools, which assist in understanding the epidemiology of Salmonella infections. In this respect, the Centre of Enterobacteriaceae of Southern Italy provides helpful information on the changing pattern of Salmonella serovars in this geographic area. This paper reports the distribution of serovars and their antibiotic susceptibility in the years 1983-1987. In particular, because of their peculiar trends during this 5-year period, epidemiological features of Mbandaka, Corvallis, Dublin, Infantis and Wien serovars are described.
Antibacterial activity of Borago officinalis and Brassica juncea aqueous extracts evaluated in vitro and in situ using different food model systems
2014
The present study was undertaken to characterize the antibacterial activity of the aqueous extracts (AEs) obtained from the leaves of Borago officinalis L. and Brassica juncea L. The antagonistic activity was evaluated against several bacteria (42 strains of Listeria monocytogenes, 35 strains of Staphylococcus aureus, 38 strains of Enterobacter spp. and 18 strains of Salmonella enterica) commonly associated with foodborne diseases by paper disc diffusion method. The susceptibility to the plant extracts was strain specific. Thirty-five strains (7 L. monocytogenes, 11 S. aureus, 1 S. Enteritidis, 1 S. Veneziana, 7 Enterobacter hormaechei, 5 Enterobacter cloacae, 1 Enterobacter sakazakii and 2…
Molecular Epidemiological Survey ofCitrobacter freundiiMisidentified asCronobacterspp. (Enterobacter sakazakii) andEnterobacter hormaecheiIsolated fr…
2011
A total of 75 powdered infant milk formula (PIF) samples collected from pharmacies and drugstores in Western Sicily, Italy, and representative of 12 different brands were analyzed in this study to evaluate their microbiological quality. According to the U.S. Food and Drug Administration protocol, 32 samples out of 75 were contaminated by enterobacteria. Commercial biochemical API(r) 20E-system identification method indicated that six PIF samples were presumptively contaminated by Cronobacter spp., but further characterization by alpha-glucosidase based polymerase chain reaction (PCR) assay identification strongly suggested that these strains did not belong to the genus Cronobacter. Phylogen…
Comparison of the exoproducts of gram-negative bacteria by SDS-page
1985
The protein exoproducts released during exponential growth of Gram-negative bacteria were analysed and compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-Page). The following bacterial strains were tested: Escherichia coli, Klebsiella pneumoniae, Citrobacter freundii, Enterobacter cloacae, Serratia liquefaciens, Serratia rubidaea, Proteus mirabilis, Proteus vulgaris, Salmonella minnesota, Pseudomonas aeruginosa and Pseudomonas fluorescens. It is demonstrated by SDS-Page that members of one species show identical protein pattern, whereas different species show besides comparable protein bands a species characteristic pattern. All members of Enterobacteriaceae were sho…