Chromogenic Bacteria Research Articles

Blue chromogenic dental staining in child with West syndrome

Tooth discolouration can be caused by a variety of local and systemic factors. Extrinsic dental stains may be caused by predisposing factors, and other factors such as dental plaque, foods and beverages, chromogenic bacteria, metallic compounds and medications. Studies have reported a correlation between the colour of extrinsic staining and caries risk. A 4-year-old boy with West syndrome, characterised by epileptic seizures and severe muscle spasm, was referred to the paediatric dentistry clinic at School of Clinical Dentistry, Sheffield. He had a percutaneous endoscopic gastrostomy (PEG) tube and had no oral food or fluid intake. The presenting complaint was his parent's concern of trauma to the oral tissues from epileptic fits. An examination revealed an unusual navy-blue staining to his teeth that appeared extrinsic in nature. There was evidence of tooth-wear of his primary dentition, and marked calculus deposits. No caries was detected. A further dental examination and treatment was carried out under general anaesthesia. The mandibular central incisors were extracted, due to imminent pulp exposure from bruxism, and were sent for histopathology to determine the nature of the staining. A moderate growth of Pseudomonas aeruginosa, a blue pigment-producing bacteria usually implicated in chronic pulmonary infections, was recovered from a swab sample. The patient was reviewed at 4 months at which time the staining had returned. The patient had no oral intake of food or drink, which placed him in a low caries risk category despite limited oral hygiene practice. His extensive lists of medications were not found to have extrinsic dental staining as a possible side effect. However, these may have altered the oral flora such that growth of pigmented bacteria, normally absent from the oral cavity, was favoured, causing generalised extrinsic staining.

The use of chromogenic bacteria as coloured substitutes for pathogens: A simple strategy during design and development of a new method for sample pretreatment

In the present study, chromogenic (red) bacteria were used to simulate actual target bacteria during set-up and optimization of an isolation process of bacteria, designed for food samples. Isolation of bacteria from food in the context of molecular biological detection of food pathogens is a multistep process. Development of such a separation method requires continuous monitoring of the location of the presumable targets in the sample tubes. Therefore, red-coloured pigmented bacteria were used as substitutes for the actual target bacteria, during the establishment of a new sample preparation technique. The chromogenic bacteria Micrococcus roseus and Serratia marcescens were confirmed to withstand the physical (e.g. centrifugal forces) and chemical (e.g. lysis buffer composition) conditions required during establishment of the new technique. Furthermore, the suitability of these model bacteria to substitute for the actual target pathogens (Salmonella enterica subsp. enterica serovar Typhimurium and Listeria monocytogenes) was assured by testing the physical properties of the model bacteria with respect to the proposed separation methods. Visibility of the pigmented bacteria within the complex sample matrices served to allocate bacterial content during the various steps necessary for finalization of the method protocol. The presumptive bacterial targets can be allocated simply by visualization of their bright red colour silhouetted against the background sample matrix. The use of pigmented bacteria as substitutes for actual colourless target bacteria during design and development of a bacterial isolation method is a simple and inexpensive application. It saves a huge amount of time and resources, as the proof of principle of new methods is possible in rapid succession.

Blue Pseudochromhidrosis Secondary to Topiramate Treatment

© 2009 The Authors. doi: 10.2340/00015555-0696 Journal Compilation © 2009 Acta Dermato-Venereologica. ISSN 0001-5555 Sir, Topiramate (TPR) is an adjunctive treatment for patients with refractory epilepsy. Several cases of hypohidrosis under TPR treatment have been reported. We describe here a new reversible side-effect on human sweating function: blue pseudochromhidrosis. Chromhidrosis and pseudochromhidrosis are rare skin disorders. Chromhidrosis refers to the excretion by the apocrine glands of sweat containing lipofuscin pigments, while the terms of pseudochromhidrosis or extrinsic chromhidrosis are used when the eccrine sweat is coloured on the surface of the skin as a result of the deposit of extrinsic dyes or paints, or by the transformation by chromogenic bacteria.

Pink-pigmented Non-fermentative Gram-negative Rods Associated with Human Infections: a Clinical and Diagnostic Challenge

Over the past several decades, the appearance of pink-pigmented bacteria in clinical specimens has gone from being a microbiologic curiosity in the clinical laboratory to the recognition of these aerobic microorganisms as etiologic agents of human disease, most notably bloodstream infections. Advances in the fields of molecular taxonomy and phylogenetics indicate that at least four distinct genera and eight different species are associated with clinical infections in susceptible patient populations. However, these bacteria are slow growing and present multiple diagnostic challenges to the microbiology laboratory including culture, isolation, and identification to species rank. This article provides a current review of these unusual non-fermentative chromogenic bacteria including their disease spectrum, taxonomy, and laboratory identification. The review also highlights the pitfalls or shortcomings we currently have in our knowledge of these microbes and their disease-producing capabilities.

Identification of Yellow-Pigmented Bacteria Isolated from Hospital Tap Water in Japan and Their Chlorine Resistance

Twenty-five yellow chromogenic strains isolated from hospital tap water samples collected nationwide were identified by partial 16S rDNA sequencing. In addition, the chlorine resistance of the isolates was experimentally investigated. The results showed that of the strains tested, 12 strains (48.0%) were Sphingomonas ursincola/natatoria, which was most frequently identified, followed by 2 strains (8.0%) of Mycobacterium frederiksbergense and 1 strain (4.0%) each of Sphingomonas adhaesiva, Sphingopyxis witflariensis and Porphyrobacter donghaensis. The other strains were not identified clearly but they belonged to the order of Alphaproteobacteria. On the other hand, the identification results by sequencing and biochemical property testing were not consistent in any of the strains, showing that it was difficult to accurately identify the yellow chromogenic bacteria in tap water based on only their biochemical properties. When the 25 isolates were exposed to 0.1 mg/l residual free chlorine for 1 minute, 22 isolates (88.0%) survived. When the CT (Concentration Time) value killing 99.99% of the bacteria was investigated in 6 of these survivors, M. frederiksbergense (Y-1 strain) was most resistant to chlorine with the CT value of 32 mg x min/l, followed by S. ursincola/natatoria (Y-7 strain) with the CT value of 3.3 mg x min/l. The CT values of Y-5 (Sphingomonas sp.), Y-27 (S. ursincola/natatoria) and Y-21 (Asticacaulis sp.) were within the range of 0.9-0.1 mg x min /l. Of the 6 strains, S. adhaesiva (Y-10) showed the weakest resistance with the CT value of 0.03 mg x min/l. It was clarified that most yellow chromogenic bacteria isolated from hospital tap water were Sphingomonas spp., and these bacteria were experimentally resistant to chlorine.

Abundance and distribution of microbial populations in sheep fleece

Bacteria were isolated and enumerated from fresh wool samples from sheep flocks throughout New Zealand. Bacterial populations averaged 108‐109 colony forming units (cfu) g‐1 wool and varied little between flocks. Highest numbers of bacteria were recovered from the back, neck, and rump of the sheep rather than the underside of the animal. Within the fleece, most bacteria (>95% of total) were isolated from the outer portion of the staple. The fleece bacteria could be divided into three broad classes, Gram‐positive cocciform bacteria, Gram‐positive rods, and Gram‐negative rods. Most bacteria from the fleece formed pigmented colonies with colours ranging from yellow to bright red. Gram‐positive cocciforms were the most abundant group of bacteria with the most common species corresponding to Kocuria rosea, Micrococcus luteus, and M. lylae. These species form a dominant complex of salt tolerant chromogenic bacteria which are characteristic of the healthy fleece.

Heavy Metal Tolerance in Chromogenic and Non-Chromogenic Marine Bacteria from Arabian Gulf

A simple method – direct agar diffusion assay – was optimised for rapid assessment of heavy metal toxicity to marine chromogenic and non-chromogenic bacteria. The procedure involved spotting of a 10 microliter test solution on the seeded agar plate and incubation of the plates at 30°C to accelerate bacterial growth. Under optimum conditions, test results were obtainable within 12–18 hr instead of 96 hr incubation time generally required for a marine bacterial assay by conventional agar plate methods. A range of sixteen heavy metals, each at 5 different concentrations was tested. Toxicity was demonstrated by the formation of a clear zone of growth inhibition around the point of application. Toxicity of tested chemicals could be easily demonstrated at concentrations as low as 0.1 μg per spot on the agar plate. A dose dependent relation between metal concentration (μg/spot) and the diameter of the clear zone on agar plate was observed, suggesting potential of this method as an easy and economical tool in quantitative toxicology studies.

Mechanisms of Stain Formation on Teeth, in Particular Associated with Metal Ions and Antiseptics

Much has been written on the subject of extrinsic tooth discoloration, but, except when the pigment is intentionally applied, the etiologies and mechanisms are poorly understood. Extrinsic stains have been classified as non-metallic or metallic. The pigment usually lies not on or in the dental tissues, but in surface deposits, particularly the acquired pellicle layer and at sites receiving limited cleaning. Whether pigments absorb, adsorb, or chemically interact with dental surfaces is unclear. Some stains merely seem to reflect the color of the apparent source, whereas others have been ascribed to a secondary chemical alteration of a substance at the tooth or pellicle surface. Theories of chromogenic bacteria and formation of metal sulfides are frequently propounded but without clear supportive evidence. Staining by cationic antiseptics and, to a lesser extent, metal salts has attracted research interest. Chlorhexidine and other cationic antiseptics, it is hypothesized, may catalyze browning reactions or facilitate metal sulfide formation in pellicle. Controlled clinical studies have repeatedly shown that dental and mucosal staining associated with the use of chlorhexidine and some metal salts is dependent upon volunteers' imbibing reasonable quantities of chromogenic beverages, such as tea. However, it must be appreciated that cationic antiseptics and polyvalent metals can precipitate chromogenic material from a large range of dietary compounds. The control of dental staining, at least that associated with chlorhexidine, can be achieved both in vitro and in vivo by the use of oxidizing agents which appear to remove the stain physically from the surfaces.

Zur besiedlung von apfelblättern, -blüten und -zweigen mit epiphytischen mikroorganismen

Summary Results of three years-lasting studies on the epiphytic microflora of apple trees (flowers, leaves and twigs) in connection with an artificial contamination by the causal agent of fire blight, Erwinia amylovora ( Burrill ) Winslow et al., are presented. By colony traits and pigmentation more than 160 groups of bacteria as well as some yeasts and filamentous fungi could be distinguished. Agreeing with the studies of Stadelmann (1976) and others in Switzerland the qualitative and quantitative alterations of the resident microflora observed mainly depended on the season. Thus, in second half of the season the concentration of chromogenic bacteria increased. In a dry year (1986) the bacteria occurring on the twigs remarkably decreased during summer and showed a typical population maximum in autumn. In the third year of monitoring (1987) only a short-term reduction of the population of epiphytic bacteria could be proved. Obviously, the differences in the colonization density between the years under test were dependent on the specific meteorological conditions of each season (years resp. periods with few or high precipitations). In all test years the epiphytic fungi showed population maxima in spring time and in autumn. The Erwinia amylovora population artificially applicated survived mostly 2, seldom 3 months on the surface of the plant organs treated. The results are discussed concerning the possible suppression of the pathogen by resident microorganisms.

Bacteriological aspects of Florida red tides: A revisit and newer obervations

A brief review is presented of the literature involving the occurrence of bactera in red tides caused by the dinoflagellate Ptychodiscus brevis. Both quantitative and qualitative studies were made on outbreaks along the Florida Gulf coast in 1982 and 1987 and a bloom along the North Carolina coast in 1987. Non-bloom waters in both areas were sampled in 1988. Bacteria were also recovered from batch cultures of P. brevis. Bacterial isolates from red tide and normal waters and dinoflagellate cultures were tested for their ability to kill fish under laboratory conditions. Numbers of bacteria were always higher than reported for a 1971 outbreak but did not routinely correlate directly with P. brevis numbers. Storage of red tide water produced increased bacteria counts in some cases and decreased levels in another. Members of the genera Aeromonas, Alteromonas/Pseudomonas, and Vibrio were frequently isolated from the three blooms studied as well as from non-bloom waters; MPN of> 1100 100 ml of Vibrio alginolyticus were recorded from the latter. Dominant chromogenic bacteria, reported during previous studies, were not observed in our samples. Several bacteria killed fish experimentally including isolates from red tide and normal waters and P. brevis cultures. It was concluded that a given dinoflagellate bloom is an individual event from a bacteriological standpoint, based on quantitative and qualitative comparison of historical observations and the present study. Recent reports of tetrodotoxin production by the bacterial genera isolated above suggests a further consideration of bacteria in toxic dinoflagellate blooms.

Prevention of Bacterial Wilt of Grasses by Phylloplane Bacteria

AbstractVarious chromogenic bacteria were isolated from the mowing site in natural and sown meadows and in pastures. Their ability to protect young ryegrass plants from wilt by simultaneous inoculation with Xanthomonas campestris pv. graminis was tested under low concentrations of the parasite inoculum. From about 200 isolates tested 35% had a very high protective effect, 45% a moderate one, and only 20% had no significant effect. Mixtures of different species of phylloplane bacteria usually gave very good protection. Most of these bacteria live between the leaf‐sheaths. In vitro antagonism of the phylloplane bacteria was not related to their protective effect. Avirulent mutant strains of X. c. pv. graminis and pathovars, of other grass species, e.g. pv. poae, pv. phlei, and pv. arrhenatheri, have the same protecting effect. Heat killed bacteria were no longer effective.These observations suggest an unspecific reaction of the plant, such as the induction of a general defense mechanism which results in resistance also to the parasite.

Composition of the bacterial flora of the rhizosphere of three grassland plants grown separately and in mixtures

In two pot experiments Lolium perenne, Plantago lanceolata and Trifolium repens were grown separately and in two-species mixtures. The rhizospheres were separated and numbers of bacteria were determined by dilution plating. In both experiments the composition of the bacterial population was influenced by what other plant species was present in the pot. For example, chromogenic bacteria were more abundant when Trifolium was the partner species than when Plantago was. A non-fluorescent pseudomonad was equally abundant on Lolium and Trifolium when they grew separately, but much commoner on Trifolium when the two plants grew together.

Effects of heavy metal pollution on the microflora of pine needles

A leaf washing method was used to compare the numbers and species composition of the phylloplane microflora of corsican pine saplings (a) uncontaminated, (b) exposed to zinc, lead and cadmium pollution from a smelter and (c) artificially dosed with zinc, lead and cadmium oxides to simulate the emissions from the smelter without the complicating effects of other pollutants. There was little difference in total numbers of most groups of micro‐organisms isolated from each site, although both sets of metal‐contaminated saplings generally supported a higher percentage of metal tolerant isolates than the uncontaminated plants. Artificially dosed plants also supported greater numbers of Aureobasidium pullulans and orange and pink chromogenic bacteria. These particular organisms were also among the most metal‐tolerant fungi and bacteria in vitro.

Numerical Taxonomy of some Yellow-pigmented Bacteria Isolated from Plants

Phenetic data on over 60 heterotrophic, Gram-negative, yellow chromogenic bacteria from plant material were collected and analysed using numerical taxonomic methods. Marker strains representing 42 taxa were included in the analyses. At similarity levels of 80% or above, eight distinct clusters were obtained, the first four of which included yellow chromogens. Custer I contained isolates from green healthy leaves of Agrostis tenuis, Festuca rubra, Holcus lanata, Lolium perenne and Poa pratensis, and clusters 2 and 3 consisted of isolates from Holcus lanata seeds and leaves of P. pratensis respectively. Cluster 4 contained seven subgroups and was equated with the family Enterobacteriaceae. Erwinia herbicola strains from a variety of sources formed a homogeneous subgroup, readily distinguishable from authentic strains of E. amylovora, E. carotovora, other representative erwiniae, and from all other enterobacteria studied. These data emphasize the heterogeneous nature of yellow-pigmented bacteria from plants, and support the inclusion of E. herbicola and other Erwinia species in the Enterobacteriaceae.

Carotenes and xanthophylls in mycobacteria. III. Influence of light on the pigment synthesis of chromogenic bacteria

The influence of light on pigment synthesis of growing photo- and scotochromogenic mycobacteria was investigated. Optimal incubation time, duration of light-exposure, influence of the medium were intensively studied. The following conclusions could be drawn. Photochromogenic mycobacteria possess a pigment synthesis which is almost completely suppressed in the dark. Beside these strains there exist so-called scotochromogenic mycobacteria, which show only a partially suppressed pigment synthesis in the dark; lightexposure provokes an increase of the pigment content, an activation of the pigment synthesizing enzyme system. These strains represent a `mixed' chromogenic type between the photo- and the true scotochromogenic mycobacteria. The most important representatives of this group are M. aquae, M. kansasii var. aurantiacum, M. scrofulaceum and M. vaccae. ‘True’ scotochromogens with pigment synthesis in the dark not suppressed cannot synthesize increased amounts of pigment under the influence of light. Among the strains investigated only M. phlei belongs to this group.

The Role of Bacteria in the Florida Red Tide

Abstract While Gymnodinium breve is generally recognized as the principal cause of Florida red tide, insufficient attention has been devoted to bacteria associated with this dinoflagellate. As a working hypothesis we propose that growth of G. breve during a bloom is stimulated by the concurrent or prior growth of marine bacteria which supply known vitamin requirements and perhaps other growth factors. After the first cycle of G. breve multiplication results in fish kills, saprophytic bacteria including red chromogens appear in response to nutrients from dying fish and invertebrates or from disintegrating G. breve cells. The red discoloration is due not to G. breve, but to chromogenic bacteria. Toxins from bacteria in the first or second stages might act in synergy with G. breve toxin. Repeating and/or overlapping cycles of these stages might be obscured in a massive bloom. Chromogenic bacteria might be inapparent in a minor bloom. From research on the red tide outbreaks of 1971 and 1972, data are presente...

Observations on the taxonomy of chromogenic bacteria isolated from cannery environments.

The yellow‐orange chromogenic bacteria, commonplace in cannery environments, are capable of producing spoilage in a variety of presterilized milk‐based canned products. A wide range of cultures of these arbitrarily defined flavobacteria, including the particular food spoilage types, were subjected to taxonomic studies. A possible scheme permitting the grouping of spoilage from nonspoilage types is presented.

The effect of high-pressure oxygen on chromogenic bacteria.

The effect of high-pressure oxygen on chromogenic bacteria.

Stimulation of Streptomycin-Resistant Bacteria in the Rhizosphere of Leguminous Plants

SUMMARY: Bacteria which were resistant to streptomycin and rose bengal were preferentially stimulated in the rhizospheres of several plant species as compared with those in the soil away from the rhizosphere. Leguminous plants were the most effective and clover plants as young as 6 days had some effect. The separate and combined effects of rose bengal and streptomycin in the isolation medium were examined. Rose bengal alone had little effect on bacterial numbers, whereas streptomycin alone decreased them. The two substances together affected rhizosphere numbers strikingly but inconsistently. The bacteria from rhizosphere and soil were grouped according to their nutritional requirements. Chromogenic bacteria with simple requirements were the most abundant forms resistant to streptomycin + rose bengal in the rhizosphere and a species of Flavobacterium was especially favoured.

Yellow chromogenic bacteria on wheat. II. Determinative studies.

The predominant type of yellow chromogenic bacteria easily isolated from normal wheat and other seeds, and in the early literature referred to as Bacterium herbicola aureum Diiggeli, is like Xanthomonas translucens in many aspects—in morphology, colony characteristics, type of pigment, and habitat. These bacteria differ from the latter species in that they are not pathogenic and they grow moderately in a medium containing asparagine as the sole source of carbon and nitrogen. The problem of nomenclature of these bacteria is considered. Evidence that justifies acceptance of Pseudomonas trifolii Huss as the legitimate name of the species and transference of the species to the genus Xanthomonas is presented. The name Xanthomonas trifolii (Huss) comb. nov. is proposed.