Cultures Of Enterobacter Cloacae Research Articles

Some Features of the Bacteria of the Family Enterobacteriaceae Allocated from Small Cattle at Different Pathological Processes

Enterobacteria with a certain set of pathogenicity factors and capable of leading to the development of diseasesof animals and humans are ubiquitous in nature, which can be recognized as the result of anthropogenicactivity. Recently, they have been isolated with increasing frequency from soil, water, from fruits,vegetables, grains, plants, from representatives of various systematic groups of animals and humans. Wehave obtained bacteria from sheep with gastrointestinal pathologies. From sick animals, we have identified alarge number of bacterial cultures belonging to species of different genera of the Enterobacteriaceae family.Among them, 190 cultures, species belonging to Escherichia coli, 124 cultures of Enterobacter cloacae,74 cultures of Morganella morganii, 51 culture of Citrobacter freundii, 29 cultures of Serratia marcescens.For these microorganisms a large set of various pathogenicity factors was characteristic: antilysocyme,anti-complementary, anti-interferon activity, adhesive ability, hemolytic activity, multiple resistance toantibacterial drugs.The aim of our work is to study the spread of enterobacteriosis, some features of the epizootic process inthese diseases in the territory of the Chechen Republic

Enumeration and Identification of Ethanol-Injured Coliform Bacteria Found on Harvest Equipment and its Cross-Contamination with Cabbage

Enumeration and Identification of Ethanol-Injured Coliform Bacteria Found on Harvest Equipment and its Cross-Contamination with Cabbage Although disinfection by sanitizers used to produce packing sheds which helps in preventing cross-contamination between farm equipment and produces, sanitizing agents like ethanol are capable of causing sanitizer-injured bacteria. Using the thin agar layer (TAL) method, the proportion of ethanol-injured coliform bacteria resulting from the use of an alcohol agent containing 1.6% and 47% ethanol was evaluated in pure cultures and in a harvest environment of cabbage, respectively. In pure cultures of Enterobacter cloacae, Escherichia coli, and E. coli O157:H7, ethanol-injured cells were observed at a range of 68-95% by treatment with an alcohol agent. When an alcohol agent was sprayed on harvest equipment including knife, container and gloves, 60% of the total coliforms detected on the knife were injured, but no injured coliforms were detected on the container and gloves. The isolation and identification of coliforms on selective and TAL media from the knife suggested that the ethanol stress caused injury to Enterobacter amnigenus, E. asburiae, and E. kobei. Injured bacteria were not detected on cabbage after harvest using the alcohol spray-treated knife because the species of bacteria found in cabbage (14 species belonging to 11 genera) were different from those on the knife. These results indicate that the sanitizer-injured coliforms would not be present on cabbage when transfer of the bacteria from harvest equipment to the cabbage is prevented or when a suitable sanitizer is used that causes death of the bacteria rather than sanitizer-induced cell injury.

Enumeration and Identification of Coliform Bacteria Injured by Chlorine or Fungicide Mixed with Agricultural Water

Chemical sanitizers may induce no injury (bacteria survive), sublethal injury (bacteria are injured), or lethal injury (bacteria die). The proportion of coliform bacteria that were injured sublethally by chlorine and fungicide mixed with agricultural water (pond water), which was used to dilute the pesticide solution, was evaluated using the thin agar layer (TAL) method. In pure cultures of Enterobacter cloacae , Escherichia coli , and E. coli O157:H7 (representing a human pathogen), the percentage of chlorine-injured cells was 69 to 77% for dilute electrolyzed water containing an available chlorine level of 2 ppm. When agricultural water was mixed with electrolyzed water, the percentage of injured coliforms in agricultural water was 75%. The isolation and identification of bacteria on TAL and selective media suggested that the chlorine stress caused injury to Enterobacter kobei . Of the four fungicide products tested, diluted to their recommended concentrations, Topsin-M, Sumilex, and Oxirane caused injury to coliform bacteria in pure cultures and in agricultural water following their mixture with each pesticide, whereas Streptomycin did not induce any injury to the bacteria. The percentage of injury was 45 to 97% for Topsin-M, 80 to 87% for Sumilex, and 50 to 97% for Oxirane. A comparison of the coliforms isolated from the pesticide solutions and then grown on either TAL or selective media indicated the possibility of fungicide-injured Rahnella aquatilis , Yersinia mollaretii , and E. coli . These results suggest the importance of selecting a suitable sanitizer and the necessity of adjusting the sanitizer concentration to a level that will kill the coliforms rather than cause sanitizer-induced cell injury that can result in the recovery of the coliforms.

Rapid Detection of Bacteria in Green Tea Using a Novel Pretreatment Method in a Bioluminescence Assay

Tea is one of the most popular beverages consumed in the world, and green tea has become a popular beverage in Western as well as Asian countries. A novel pretreatment method for a commercial bioluminescence assay to detect bacteria in green tea was developed and evaluated in this study. Pretreatment buffers with pH levels ranging from 6.0 to 9.0 were selected from MES (morpholineethanesulfonic acid), HEPES (N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid), or Tricine buffers. To evaluate the effect of pretreatment and the performance of the assay, serially diluted cultures of Enterobacter cloacae, Escherichia coli, Bacillus subtilis, and Staphylococcus aureus were tested. The improved methods, which consisted of a pretreatment of the sample in alkaline buffer, significantly decreased the background bioluminescence intensity of green tea samples when compared with the conventional method. Pretreatment with alkaline buffers with pH levels ranging from 8.0 to 9.0 increased the bioluminescence intensities of cultures of E. cloacae and S. aureus. Strong log-linear relationships between the bioluminescence intensities and plate counts emerged for the tested strains. Furthermore, the microbial detection limit was 15 CFU in 500 ml of bottled green tea after an 8-h incubation at 35°C and an assay time of 1 h. The results showed that contaminated samples could be detected within 1 h of operation using our improved bioluminescence assay. This method could be used to test for contamination during the manufacturing process as well as for statistical sampling for quality control.

Remediation of textile waste water using MFC technology by addingEnterobacter cloacae

Remediation of textile industrial waste water using a Microbial Fuel Cell (MFC) with 0.4% sodium acetate as substrate is described. In this study, waste water samples from textile industry have been used with varying optical densities of Enterobacter cloacae to assess the bio-remediation efficiency and electrical potential. Textile waste water was found to generate voltage of 502.1 mV which increased to 801.33 mV when pellet of 100 mL Enterobacter cloacae culture was mixed with textile waste water in anodic chamber. Coulombic efficiency of textile waste water alone was 57%, which increased to 80.1% with textile waste water containing 100 mL Enterobacter cloacae pellet. The present study clearly demonstrated that remediation of waste water using MFC technology can be greatly improved by the addition of Enterobacter cloacae as revealed by a decrease in COD value

Evaluation of full-strength paper mill effluent for electricity generation in mediator-less microbial fuel cells

In the search for renewable, sustainable and affordable energy sources, microbial fuel cells (MFCs) offer the advantage of a biological oxidation of pollutants to the direct generation of electricity by microorganisms. We thus examined the biodegradability and suitability of unamended paper mill effluent for power production in MFCs. In addition, an investigation of the response from indigenous waste microbes upon introduction of an exogenous Enterobacter cloacae culture was performed. Unamended effluent alone reached a substrate degradation rate (SDR) of 0.112 kg COD/m 3 day and 29.4 ± 2.4% total chemical oxygen demand (tCOD) removal, the power density peaked at 24 ± 3 mW/m 2 and 47.7% glucose increase at the termination of the reactor cycle after 12 ± 3 days. The introduction of E. cloacae in separate setups lowered electricity generation, but benefited remediation, power density decreased to 13 ± 2 mW/m 2 whereas the SDR increased to 0.257 kg COD/m 3 day. Also, there was 44.1% glucose removal in the presence of E. cloacae . It was concluded that unamended paper mill effluent can fuel electricity generation in MFCs with its concomitant remediation. The addition of E. cloacae to live paper mill effluent may be antagonistic in terms of electricity generation. Key words: Microbial fuel cells, paper mill effluent, bioremediation, substrate degradation rate, wastewater, renewable energy, electricity.

The effects of bee ( Apis mellifera) venom phospholipase A2 on Trypanosoma brucei brucei and enterobacteria

The potential role of phospholipases in trypanosomiasis was investigated using bee venom phospholipase A2 (bvPLA2) as a model. The effects of bvPLA2 on the survival of Trypanosoma brucei brucei, 2 h and 12 h cultures of Enterobacter cloacae, Escherichia coli, Citrobacter freundii were studied. About 1 mg ml −1 bvPLA2 was trypanocidal after 30 min. Some growth occurred at lower concentrations up to 2 h after treatment but viability decreased up to 8 h. Even very low concentrations of bvPLA2 (10 −12 mg ml −1) had some trypanocidal activity. Bee venom PLA2 was bactericidal to 2 h bacterial cultures but bacteriostatic to 12 h ones. Minimum bactericidal concentrations were 10 −5–10 −6 mg ml −1. The results showed that bvPLA2 had significant trypanocidal and antibacterial effects on Gram-negative bacteria. The relationship to events occurring during infection is discussed. Phospholipases may play a role in increased endotoxin levels in trypanosomiasis.

Induction of Oxidative Stress in Leukocytes by an Enterobacter cloacae Toxin Able to Form Oligomers and Binding to Proteins

A leukotoxic and hemolytic toxin was purified from cultures of Enterobacter cloacae. Stimulation of oxidative stress was observed and the production of reactive oxidant species was measured in leukocytes treated with toxin by means of nitroblue tetrazolium and chemiluminescence assays. Molecular weight of toxin was estimated by chromatography and SDS–PAGE. Two protean peaks with toxic activity were found in Sephadex G-100 (P1, 42.0 kDa; and P2, 13.3 kDa). The relative amounts between the peaks (P1/P2 = 0.36) changed when 2-mercaptoethanol was employed (P1/P2 = 0.59). When Sephadex G-200 chromatography was performed, a protean peak of Ve = 113 mL (100 kDa) was found; its was dissociated with 3 M urea in toxic proteins of lower mass: 42, 27, and 13.3 kDa. SDS–PAGE (15%) showed a single toxin band of purified monomer (13.3 kDa), but electrophoresis of a 42-kDa toxin with urea presented three bands of trimer, dimer, and monomer. An increase of casein hydrolysate and albumin molecular weight was observed by chromatography after incubation with toxin due to the binding of both proteins with toxin.

Antibiotic-induced release of endotoxin from bacteria in vitro.

The ability of cefotaxime, ciprofloxacin, piperacillin and tobramycin to cause release of endotoxin was examined in vitro with cultures of Enterobacter cloacae and Escherichia coli. Endotoxin was measured by a quantitative limulus amoebocyte lysate assay and its presence was confirmed by silver staining of the lipopolysaccharide moiety following SDS-PAGE. The morphology of the bacteria during antibiotic exposure was examined by scanning electronmicroscopy. Cefotaxime, ciprofloxacin and piperacillin caused significant endotoxin release, correlating with their ability to affect cell-wall morphology, causing filamentation, wall breakage and cell lysis. In contrast, little endotoxin was released when bacteria were exposed to tobramycin and no morphological changes were observed when bacteria were exposed to bactericidal concentrations of this aminoglycoside. Its antimicrobial spectrum and bactericidal activity make tobramycin an appropriate agent for treatment of sepsis caused by gram-negative bacteria and its lack of propensity to elicit excessive release of endotoxin may avoid exacerbation of endotoxin-related shock in sepsis.

IAA biosynthetic pathway from tryptophan via indole-3-pyruvic acid in Enterobacter cloacae.

Indole-3-acetic acid (IAA) was identified as a tryptophan (Trp) catabolite in the cultures of Enterobacter cloacae isolated from the rhizosphere of well-grown cucumbers. This strain produced IAA in a tryptophan-supplemented liquid medium at levels of up to 1 mg/ml, and indole-3-lactic acid (ILA) and tryptophol (Tol) were also produced. Under aerobic conditions, IAA was produced in higher concentrations than ILA and Tol, but under less aerobic conditions, ILA and Tol were produced in higher concentrations than IAA. In metabolic studies with eight kinds of indole substrates, E. cloacae converted Trp, indole-3-pyruvic acid (IPyA), and indole-3-acetaldehyde (IAAld) to IAA. These results strongly suggest that the biosynthesis of IAA in E. cloacae involves the pathway of Trp to IAA via IPyA and IAAld.

Effects of Increased Major Histocompatibility Complex Dosage on Chicken Monocyte-Macrophage Function

The influence of major histocompatibility complex (B complex) dosage on monocyte-macrophage function was examined using 4- to 6-week-old trisomic strain chickens. Di- (B15B15), tri- (B15B15B15), and tetrasomic (B15B15B15B15) progeny were produced from trisomic x trisomic crosses. Although mononuclear leukocytes from tetrasomics exhibited enhanced chemotactic activity in response to both f-met-leu-phe and Enterobacter cloacae culture supernatant as compared with that of cells from other groups, the ability to generate peritoneal exudate cells in response to intraperitoneal Sephadex stimulation was similar in all groups. Among peritoneal exudate cells, tetrasomic birds produced a significantly lower percentage of adherent macrophages with a higher proportion of Fc receptor-positive and CMTD-2-reactive macrophages than either disomic or trisomic chickens. Both tetrasomic and trisomic peritoneal macrophages exhibited a reduced phagocytic activity for unopsonized but not opsonized SRBC than was found with disomic macrophages. Thus, the number of major histocompatibility complex copies present in cells appears to influence monocyte-macrophage function.

Chemotactic activity of chicken blood mononuclear leukocytes from 15I 5- B-congenic lines to bacterially-derived chemoattractants

The chemotactic activity of chicken blood mononuclear leukocytes was examined in partially-developed 15I 5- B-congenic chicken lines using Enterobacter cloacae culture supernatant and formyl-methionyl-leucyl-phenylanine (f-met-leu-phe) (10 −5 M). Cells from seven different coded B-congenic lines were used to study each chemoattractant in vitro. Mononuclear cells from lines .15I- B 5,.C- B 12 and the background line 15I 5 ( B 15) exhibited a significantly greater directed migration to bacterial supernatant than did cells from four lines carrying the B 2, B 2, B 13, and B 19 haplotypes, respectively. Similarly response to f-met-leu-phe was greatest in lines .15I- B 5, .C- B 12 and .N- B 21, with the same four lines exhibiting a significantly lower response. Since f-met-leu-phe was originally isolated from bacteria, the results indicate that these lines possess differential chemotactic responses to certain bacterially-derived chemoattractants. Major histocompatibility complex (MHC) differences between the lines may serve as a genetic basis for the differential responses. Extrapolation of these results to other chemotactic-receptor systems would require further examination.

Siderophore production by Enterobacter cloacae and a common receptor protein for the uptake of aerobactin and cloacin DF13.

Iron-starved cultures of Enterobacter cloacae produced two siderophores, identified as enterochelin and aerobactin. The aerobactin was excreted in larger amounts than was enterochelin, and it was synthesized preferentially in the late logarithmic and stationary growth phases under iron-deficient conditions. Enterochelin was synthesized by cultures in the logarithmic phase of growth and preferentially in medium with 1 microM ferric chloride. Both siderophores appeared to be excreted immediately after their synthesis, since no intracellular aerobactin or enterochelin could be detected. The killing activity of the bacteriocin cloacin DF13 was inhibited by aerobactin. It was shown that aerobactin and cloacin DF13 bound to the same receptor sites located in the outer membrane. The synthesis of these receptor sites was induced by iron limitation. We conclude that the receptor for the uptake of aerobactin also functions as receptor for cloacin DF13.