Biochemical Properties and Colony Formation Patterns of Salmonella-Like Strains.
0
Citation
12
Reference
10
Related Paper
Abstract:
Five bacterial strains were isolated from food samples, and were not easily distinguished from Salmonella via conventional methods. These bacterial strains wereidentified as Citrobacter spp. from their biochemical properties. Despite this, their characteristics after being cultured resembled those of Salmonella, with similar kinds of colony formation patterns on XLD, DHL and TSI agar. Since these salmonella-like strains grew at a rate and produced colonies with black centers characteristic of Salmonella, the selective detection of Salmonella in the presence of these salmonella-like strains was impossible, based on conventional methods.Keywords:
Citrobacter
The authors isolated two strains of an unnamed bacterial biotype with characteristics intermediate between those of Enterobacter and Citrobacter. The organisms did not produce acetyl-methyl carbinol, but decarboxylated lysine. Apart from the latter trait, they most closely resemble H2S-negative Citrobacter freundii. They differ biochemically from all other currently accepted species of enterobacteriaceae. Their pathogenic significance appears similar to that of the two genera they most closely resemble. Only by recognition and study of additional strains can their identity be more definitively delineated and their significance more fully assessed.
Citrobacter
Citrobacter freundii
Cite
Citations (18)
To develop a new method for rapid screening suspicious Salmonella. Using L-pyroglutamic acid(PYR) as a substrate fixed on paper disc to detect the enzyme activity on enterobacterial isolated plates to distinguish Salmonella from citrobacter and other enterobacteriaceae. Comparison were made between the standard method and PYRase test in detecting the presence of Salmonella in naturally contaminated food samples. 388 strains of Salmonella and 100 strains of other bacteria were examined. All of the Salmonella's PYRase were negative (without color), and all of the Citrobacter colonies were PYRase-positive(red colour). This test could be accomplished within 2 min after adding the develop reagent. A PYRase test was used to exam Salmonella like colonies isolated on selective agar plate from contaminated food samples,the sensitivity was 100% and the specificity and was 88.89%. [Conclusion] L-PYRase test is a rapid, accurate and simple method for screening Salmonella.
Citrobacter
Cite
Citations (0)
Isolates of a recently recognized species of Enterobacteriaceae, Citrobacter diversus, were studied in terms of their biochemical characteristics and their role in human infections. Members of this species do not produce hydrogen sulfide, but they do produce indole and ornithine decarboxylase and ferment adonitol, which differentiates them from similar enteric organisms. They were associated with significant clinical disease causing both primary and secondary infections.
Citrobacter
Enterobacteriaceae Infections
Cite
Citations (24)
In the routine testing of foods for Salmonella, Citrobacter and other members of the Enterobacteriaceae often produce colonies which are almost indistinguishable from Salmonella on commonly used selective agars. Biochemical confirmation of such colonies can be expensive and time-consuming. It has been suggested that the enzyme pyrrolidonyl peptidase (PYRase) could be used as a rapid test to distinguish Citrobacter colonies (PYRase-positive) from Salmonella (PYRase-negative). Pure cultures of Salmonella, Citrobacter and other Enterobacteriaceae were tested for PYRase activity; all strains of Salmonella tested were PYRase-negative, and all Citrobacter tested were PYRase-positive. Inoculated and naturally contaminated food samples were tested for the presence of Salmonella by a standard cultural method. A PYR test was used to test Salmonella-like colonies isolated on selective agar and potentially, eliminate PYR-positive isolates from further biochemical testing. The test was able to screen out 6% of colonies selected from samples inoculated with Salmonella, and 43% of colonies selected from uninoculated samples.
Citrobacter
Citrobacter freundii
Cite
Citations (19)
A simple, rapid, and inexpensive spot test incorporating the substrate pyrrolidonyl naphthylamide was used to examine pyrrolidonyl peptidase activity among 800 bacterial strains belonging to the families Enterobacteriaceae and Vibrionaceae. The pyrrolidonyl naphthylamide test was found to be particularly useful in separating Citrobacter spp. (100% positive) from Salmonella spp. (0.4% positive) and Escherichia coli (0% positive). Furthermore, it would appear to offer a safer alternative to the traditional potassium cyanide test for differentiating citrobacters from salmonellae.
Citrobacter
Citrobacter freundii
Escherichia
Cite
Citations (20)
A 2.3 kilobase (kb) Salmonella probe, JEO402-1, and two subfragments, F1214 (1.3 kb) and F1217 (0.8 kb), have been evaluated by colony hybridization using pure cultures of Salmonella serovars and non-salmonella bacteria. JEO402-1, and its subfragments, F1214 and F1217, hybridized to all of 156 different Salmonella serovars tested, while there was no reaction to 112 non-salmonella strains belonging to 19 genera and 37 species of Enterobacteriaceae. Together with previously published results, the JEO402-1 probe has now been shown to detect a total of 396 Salmonella strains belonging to 214 serovars of Salmonella subspecies I-VI. A total of 178 non-salmonella strains representing 23 genera and 51 species of Enterobacteriaceae have all tested negative with JEO402-1. The hybridization results obtained using a digoxigenin-labeled probe were similar to those obtained with 35S isotopic labeling when complete colony lysis was ensured.
Hybridization probe
Digoxigenin
Salmonella enterica
DNA–DNA hybridization
Subspecies
Cite
Citations (13)
Enterobacteriaceae is a large family of gram-negative bacteria. The more familiar bacteria in this family are Escherichia coli, Salmonella, Shigella, Klebsiella and Yersinia pestis. This family also consist of disease-causing bacteria such as Proteus, Serratia, Citrobacter and Enterobacter. The infection caused by Enterobacteriaceae can be transmitted through the gastrointestinal tract, urinary tract and also respiratory tract. Long Bedian is a village situated at Baram. There are about 1,500 people living in this village. Besides, there are also tourists who go to Long Bedian for the natural environment all year long. The water from the river is their main source of water for daily living. Thus, the aim of this study is to isolate the bacteria found in the water sample collected from river in Long Bedian. The species of Enterobacteriaceae present in the water sample were identified to study the hazard pose by these Enterobacteriaceae to the public. From the result obtained, there were majority of Enterobacter, Klebsiella, Citrobacter, and Serratia, which are opportunistic pathogen. Therefore, prevention step is suggested in order to secure the health of the people in Long Bedian, Sarawak.
Citrobacter
Serratia
Klebsiella
Citrobacter freundii
Pantoea agglomerans
Cite
Citations (0)
The production of bacteriolytic enzymes by Enterobacteriaceae in various growth conditions was investigated. Peptone-based media containing killed Gram-negative cells facilitated detection of bacteriolytic enzyme production in the highest number of species. These belonged to the genera Serratia, Proteus, Morganella and Providencia. In contrast, Escherichia coli, Shigella, Salmonella, Klebsiella, Enterobacter and Citrobacter species did not produce bacteriolytic activities in any of the conditions tested.
Citrobacter
Serratia
Providencia
Klebsiella
Cite
Citations (9)
Citrobacter
Serratia
Klebsiella
Yersinia
Cite
Citations (2)
The spread and quantitative content of opportunistic microorganisms belonging to the families Enterobacteriaceae and Pseudomonadaceae in clinically healthy persons and in somatic patients with intestinal dysbacteriosis were studied. Opportunistic enterobacteria were shown to be widely spread in healthy persons (K. pneumoniae in 45%, Citrobacter in 44%, E. aerogenes in 17%, E. cloaceae in 11%). In clinically healthy persons most of these cultures (72.3%) were detected in an amount not exceeding 1 X 10(4) organisms per 1 g of feces, while in patients with intestinal dysbacteriosis opportunistic enterobacteria were detected in most cases (70.9%) in an amount of 1 X 10(5)--1 X 10(8) organisms per 1 g of feces. The results of this study suggest that the presence of the opportunistic enterobacteria K. pneumoniae, Citrobacter, E. aerogenes and E. cloaceae in an amount not exceeding 1 X 10(4) organisms per 1 g of feces is normal for healthy persons, while the increase of their presence in the intestine to 1 X 10(6)--1 X 10(8) is indicative of intestinal dysbacteriosis.
Citrobacter
Enterobacter aerogenes
Citrobacter freundii
Cite
Citations (0)