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Faecal (FM) and colon mucosal associated microbiota (MAM) were studied in a model of colorectal cancer (CRC), the Apc-mutated Pirc rats, and in age-paired wt F344 rats. Principal Coordinates Analysis indicated that samples' distribution was driven by age, with samples of young rats (1 month old; without tumours) separated from older ones (11-month-old; bearing tumours). Diversity analysis showed significant differences between FM and MAM in older Pirc rats, and between MAM of both Pirc and wt rats and the tumour microbiota, enriched in Enterococcus, Escherichia/Shigella, Proteus and Bifidobacteriaceae. In young animals, Pirc FM was enriched in the genus Delftia, while wt FM was enriched in Lactobacillus and Streptococcus. Some CRC biomarkers and faecal short chain fatty acids (SCFAs) were also measured. Colon proliferation and DClK1 expression, a pro-survival mucosal marker, were higher in Pirc than in wt rats, while the mucin MUC2, was lower in Pirc rats. Branched SCFAs were higher in Pirc than in wt animals. By Spearman analysis CRC biomarkers correlated with FM (in both young and old rats) and with MAM (in young rats), suggesting a specific relationship between the gut microbiota profile and these functional mucosal parameters deserving further investigation., (© 2022. The Author(s).)

Nitrogen is the key factor for plant survival and growth, especially in the desert. Stipagrostis pennata, a sand born drought-resistant plant, could colonize pioneerly in Gurbantunggut Desert during revegetation. One strategy for their environment adaptation was the rhizosheath formatted by root-hair, mucilaginous exudates, microbial components, and soil particles, for which not only provides a favorable living microenvironment but also supplies essential nutrients. To understand the relationship between microorganisms living in rhizosheaths and the nitrogen nutrition supply, the microbial diversity and nitrogenase activity was estimated during the growth of S. pennata. Five samples of the rhizosheath, which based on the development periods of the plant, regreen, flowering, filling, seed maturating, and withering period, were collected. The nitrogenase activity was estimated by acetylene reduction and the microbial diversity was analyzed by 16S rRNA high-throughput sequencing. The results showed that the nitrogenase activity was increased slowly during regreen to flowering, while reached a peak rapidly at filling sample and then decreased gradually. A total of 274 operational taxonomic units (OTUs) were identified and significant differences in community structure and composition at each growth period. Among them, the main phyla included Actinobacteria and Proteus, which were the most abundant phyla in all periods. In addition, the microbial diversity in the grain filling period was higher than other periods in view of the analysis of alpha diversity and beta diversity. Furthermore, principal component analysis (PCA) analysis showed that the microbial communities in the filling period was low in similarity with other periods. Most importantly, the OTUs associated with nitrogen fixation is the most during the filling period, involving Phagecidae and Fucoraceae. Overall, the study not only revealed the differences in nitrogenase activity among different developmental periods in S. pennata, but also explored the potential bridges between it and community structure and diversity of bacteria., (© 2019 Wiley Periodicals, Inc.)

Stone formation and catheter blockage are major complications of Proteus UTIs. In this study, we investigated the ability of allicin to inhibit P. mirabilis-induced struvite crystallization and catheter blockage using a synthetic bladder model. Struvite crystallization inhibition study was carried out using P. mirabilis lysate as urease enzyme source in synthetic urine (SU). Struvite productions were monitored by phase contrast light microscopy and measurements of pH, Mg 2+ and Ca 2+ precipitation and turbidity. A catheter blockage study was performed in a synthetic bladder model mimicking natural UTI in the presence of allicin at sub-MIC concentrations (MIC = 64 μg/ml). The results of crystallization study showed that allicin inhibited pH rise and consequently turbidity and precipitation of ions in a dose-dependent manner. The results of catheter blockage study showed that allicin at sub-MIC concentrations (2, 4, 8 μg/ml) significantly increased the time for catheter blockage to occur to 61, 74 and 92 h respectively compared to allicin-free control (48 h). In a similar way, the results showed that allicin delayed the increase of SU pH level in bladder model in a dose-dependent manner compared to allicin-free control. The results also showed that following the increase of allicin concentration, Mg 2+ and Ca 2+ deposition in catheters were much lower compared to allicin-free control, further confirmed by direct observation of the catheters' eyehole and cross sections. We conclude that allicin prevents the formation of Proteus-induced urinary crystals and the blockage of catheters by delaying pH increase and lowering Mg 2+ and Ca 2+ deposition in a dose-dependent manner., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The aim of this study was to isolate and investigate the bacteriocinogenic and probiotic potential of new Gram-negative isolates. Of 22 bacterial isolates from pig intestine and chicken crops, ten isolates had demonstrated a good activity, and the most potent five strains were identified as four E. coli and one as Proteus sp. No virulence factors were detected for E. coli strains isolated from pig intestine. The semi-purified microcins proved to be resistant to temperature and pH variation, but sensitive to proteolytic enzymes. Of particular interest, strain E. coli P2C was the most potent, free of virulence genes and sensitive to tested antibiotics. Purification procedure revealed the presence of a single pure peak having a molecular mass of 8733.94 Da and matching microcin V (MccV). The sequence obtained by LC-MS/MS confirmed the presence of MccV. Purified MccV showed a good activity against pathogenic coliforms, especially E. coli O 1 K 1 H 7 involved in avian colibacillosis. The present study provides evidence that E. coli strains isolated from pig intestine produce microcin-like substances. E. coli P2C is a safe MccV producer that could be a good candidate for its application as novel probiotic strain to protect livestock and enhance growth performance.

Disulfides from Allium stipitatum, commonly known as Persian shallot, were previously reported to possess antibacterial properties. Analogues of these compounds, produced by S-methylthiolation of appropriate thiols using S-methyl methanethiosulfonate, exhibited antimicrobial activity, with one compound inhibiting the growth of Mycobacterium tuberculosis at 17 µM (4 mg L -1 ) and other compounds inhibiting Escherichia coli and multi-drug-resistant (MDR) Staphylococcus aureus at concentrations ranging between 32-138 µM (8-32 mg L -1 ). These compounds also displayed moderate inhibitory effects on Klebsiella and Proteus species. Whole-cell phenotypic bioassays such as the spot-culture growth inhibition assay (SPOTi), drug efflux inhibition, biofilm inhibition and cytotoxicity assays were used to evaluate these compounds. Of particular note was their ability to inhibit mycobacterial drug efflux and biofilm formation, while maintaining a high selectivity towards M. tuberculosis H37Rv. These results suggest that methyl disulfides are novel scaffolds which could lead to the development of new drugs against tuberculosis (TB).

For the purpose of safe modulation of the intestinal microflora, probiotics have been increasingly used in recent years. In the present work, the effect of the probiotic sporobacterin (Bacillus subtilis 534) (I group) and soybean-bifidum (Bifidobacterium longum) (II group) on male rats of the Wistar line was evaluated. In assessing nonspecific immunity in vitro, there was an increase in the level of baseline level in the first and second groups (by 8.3 and 12.2% more control). The influence of probiotic preparations on the intestinal normoflora was assessed using PCR. Bifidumbacterin increased the normal microflora, in particular, Escherichia coli 1.55 times, Lactobacillus 1.26 times, Enterococcus 1.3 times as much control; the level of conditionally pathogenic microflora, in particular, Proteus spp. decreased by 1.3 times in comparison with the control. Sporobacterin also contributed to an increase in the amount of E. coli (1.55 times) and Lactobacillus (0.9 times). When a culture of Bifidobacterium longum was introduced, a selective reduction in the loss of chemical elements was observed against the background of the diet used. At the end of the experiment, the content of calcium in the body tissues of animals of group II exceeded this indicator in group I by 3.9%, phosphorus by 17.6%, copper by 28.5%, and zinc by 15.2%. The totality of the results obtained by us indicates that inclusion of Bifidumbacterium longum in the diet of animals makes the use of this preparation in the correction of mineral imbalance and improves the microflora of the intestines of animals by reducing the number of representatives of opportunistic microflora against the background of an increase in the number of basic representatives of normal microbiocenosis. Also, the use of probiotic drugs as additives leads to a slight increase in the level of nonspecific immunity, which increases the natural resistance of the organism.

Agricultural activities lead excessive emission of ammonia nitrogen in the environment and can profoundly interfere the equilibrium of the natural ecosystems leading to their contamination. Actually, the biological purification of wastewaters is the most adopted technique thanks to its several advantages such as high performance and low energy consumption. For this reason, two novel strains of Alcaligenes sp. S84S3 and Proteus sp. S19 genus were isolated from an activated sludge and applied in the treatment of ammonium and nitrite in aqueous solution. Under the optimum operating conditions of temperature (30 °C), pH (7), carbon substrate (2 g/L of glucose) and duration of incubation time (69 h), the strain Alcaligenes sp. S84S3 could oxidize 65% of the ammonium as high as 272.72 mg-NH4(+)/L. Moreover, during 48 h, the nitrate reduction rate performed by the strain Proteus S19 was about 99 % without production of nitrite intermediate (negligible concentration). Moreover, the coculture of the strains Alcaligenes sp. S84S3 and Proteus sp. S19 could eliminate 65.83% of the ammonium ions without production of toxic forms of nitrogen oxides during a short time of incubation (118 h) at the same operational conditions with providing the aeration in the first treatment phase. The coculture of our isolated strains is assumed to have a good potential for nitrification and denitrification reactions applied in the treatment of wastewater containing ammonium, nitrite and nitrate. As a result, we can consider that the mixed culture is a practical method in the treatment of high-strength ammonium wastewater with reducing of sludge production.

Bacteriological analysis was conducted in 136 patients with an acute purulent cholangitis (APCH). The APCH causes were: choledocholithiasis--in 40 (29.9%) patients, coexistence of a common biliary duct stricture and choledocholithiasis--in 39 (28.7%), compression of external biliary ducts by the oedematous pancreatic head in secondary pancreatitis--in 15 (11%), pericholedocheal lymphadenitis--in 3 (2.2%).

Aim: To study the effect of Nocardia vaccinii IMV B-7405 surfactants on some bacteria (including pathogens of genera Proteus, Staphylococcus, Enterobacter), yeast of Candida species and fungi (Aspergillus niger R-3, Fusarium culmorum T-7)., Methods: The antimi- crobial properties of surfactant were determined in suspension culture by Koch method and also by index of the minimum inhibitory concentration. Surfactants were extracted from supernatant of cultural liquid by mixture of chloroform and methanol (2:1)., Results: It is shown that the antimicrobial properties of N. vaccinii IMV B-7405 surfactant depended on the degree of purification (supernatant, solution of surfactant), concentration and exposure. Survival of Escherichia coli IEM-1 and Bacillus subtilis BT-2 (both vegetative cells and spores) after treatment for 1-2 hours with surfactants solution and the supernatant (the surfactant concentration 21 µg/ml) was 3-28%. Minimum inhibitory concentrations of N. vaccinii IMV B-7405 surfactants on studied bacteria, yeast and micromycetes were 11.5-85.0; 11.5-22.5 and 165.0-325.0 µ/ml respectively., Conclusions: Minimum inhibitory concentrations of N. vaccinii IMV B-7405 surfactants are comparable to those of the known microbial surfactants. The possibility of using the supernatant of culture liquid as an effective antimicrobial agent noticeably simplifies and reduces the cost of the technology of its obtaining.

Three isolates viz. Lysinibacillus sp. HT13, Alcaligenes sp. HT15 and Proteus sp. HT37 isolated from fish processing effluent and having a C/N ratio of 2, removed 218, 169, and 400 µg cell(-1) day(-1) NH4(+)-N, respectively without subsequent build up of nitrite or nitrate. Ability of the selected isolates in removing NH4(+)-N, NO2(-)-N, and NO3(-)-N was checked in the presence of four commonly reported and tested effluent carbon sources viz. pyruvate, glycerol, methanol, and acetate. Further, when supplemented to fish processing wastewater containing 234 ppm total Kjeldahl's nitrogen, Lysinibacillus sp. HT13, Alcaligenes sp. HT15, and Proteus sp. HT37 could remediate 95.74, 86.17, and 76.6% nitrogen, respectively in 48 h. This is the first report of a Lysinibacillus sp. carrying out aerobically the process of simultaneous nitrification and denitrification. The results demonstrate the potential of the isolates for use in treatment of fish processing effluents and demonstrating the efficient removal of ammonia., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

N-acylated homoserine lactonases are known to inhibit the signaling molecules of the biofilm-forming pathogens. In this study, gold nanoparticles were coated with N-acylated homoserine lactonase proteins (AiiA AuNPs) purified from Bacillus licheniformis. The AiiA AuNPs were characterized by UV-visible spectra, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The synthesized AiiA AuNPs were found to be spherical in shape and 10 to 30 nm in size. Treatment with AiiA protein-coated AuNPs showed maximum reduction in exopolysaccharide production, metabolic activities, and cell surface hydrophobicity and potent antibiofilm activity against multidrug-resistant Proteus species compared to treatment with AiiA protein alone. AiiA AuNPs exhibited potent antibiofilm activity at 2 to 8 μM concentrations without being harmful to the macrophages. We conclude that at a specific dose, AuNPs coated with AiiA can kill bacteria without harming the host cells, thus representing a potential template for the design of novel antibiofilm and antibacterial protein drugs to decrease bacterial colonization and to overcome the problem of drug resistance. In summary, our data suggest that the combined effect of the lactonase and the gold nanoparticles of the AiiA AuNPs has promising antibiofilm activity against biofilm-forming and multidrug-resistant Proteus species., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

The results of biological research of colon microbiota of patients with rheumatoid arthritis (RA) is in article presented. The signs of III degree dysbiosis, by reducing the concentration of Bacteroides spp., Bifidobacterium spp., Lactobacillus spp. populations, typical strain E. coli. But over growth of populations Klebsiella spp., Proteus spp., Staphylococcus spp., atypical forms of E. coli, Candida spp. The scheme for the correction of the colon microflora of patients with (RA) by was proposed bifiform. Increasing of populations concentration of Bifidobacterium spp., Bacteroides spp., Lactobacillus spp., typical E. coli, Enterococcus spp. and selective decontamination of Enterococcus (Hly+), Klebsiella spp., Proteus spp., Staphylococcus spp., lactosonegative and E.coli (Hly+) confirmed after using of this eubiotics.

The study was carried out concerning capability of 194 strains of opportunistic microorganisms to form bio-films. It is established that bacteria ecizing organism of patients with rheumatic diseases have capacity to form microbial bio-films. The formation of bio-films is manifested with the same rate as in agents of inflammatory processes. At that, Escherichia coli, Staphylococcus haemolyticus and bacteria of genus Proteus isolated under rheumatic diseases have significantly higher capability to form biofilms that matters for development of comorbide infections.

Ofloxacin susceptibility was tested with the use of 100 hospital isolates by the disk diffusion method vs. the activity of Oflomelid ointment tested by the cavity method. It was shown that the hospital isolates of all the species were susceptible to the Oflomelid ointment, while susceptibility to ofloxacin was preserved in S. epidermidis, the susceptibility of Acinetobacter spp., E. coli, Proteus spp. being intermediate. Such a difference in the susceptibility of the isolates was evidently due to the properties of polyethylene glycols in the ointment composition.

The novel bioelectricity-generating bacterium of Proteus hauseri ZMd44 has been first identified to produce McoA-laccase (EC 1.10.3.2) induced by copper sulphate. The optimal concentration of copper is 3 mM as supplementation at the beginning of culture or early exponential growth phase, during which laccase is predominantly synthesized. Moreover, the whole cellular and intracellular activities of laccase increase in the degrees of inducible copper concentrations. A possible mechanism for this phenomenon is that copper ions enhance the laccase genetic transcription level during the laccase synthesis thus granting this strain in copper tolerance. McoA-laccase belongs to typical type 1 (T1) Cu site laccase by electron paramagnetic resonance (EPR) analysis of intracellular enzyme. From our results, the optimal temperature and pH are 60°C and pH 2.2, respectively. The kinetic profiles show that this enzyme is stable under 50°C and in the slightly acidic environment, making it a potentially useful enzyme in dye decolorization, paper-pulp bleaching and bioremediation industries., (Copyright © 2012 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)

Aim: Study of taxonomical structure ofwound infection agents, prevalence of mixes, and detection of character of their possible connection with the results of various microorganisms population interaction in septic wounds., Materials and Methods: A microbiological study of material from patients with wound infection (WI), 582 of those were cured in reanimation and intensive therapy departments (RITD; group 1) and 1455 - in surgical departments (SD; group 2), was performed. Taxonomic membership and ability to coexist was determined in 4129 microorganisms strains. Etiological role of the agents was evaluated by using values of consistency rate (CR). Species that were present in more than 50% of samples were considered consistent, in 25 to 50%--additional, and in less than 25%--random. Frequency rates (FR) were also determined, that is the fraction of a certain species (genus) of the microorganism (in %) from all the isolated cultures that correspond to 100%. For the determination of the significance of individual species of the agent in the structure of mixed microorganism populations, FR - their fraction (%) in mixed population from the number of strains of this species that correspond to 100% - was calculated., Results: A significant part of the microorganisms strains, more frequently in reanimation department (65.5%), caused wound suppuration in populations mixed with other species of the agents. In reanimation and surgical departments consistent species of wound infection agents were not detected. A leading etiological role of Staphylococcus aureus (FR 19.2% and 23.9%) was determined, and FR of S. aureus strains in mixes was 64.6% in RITD and 46.8% in SD. The parameters ofotheragents of WI in the comparison groups were similar. However FR among mixes in RITD were significantly higher for streptococci that do not belong to S. pyogenes species (72,5%), and also nonfermentative microorganisms (67,2%), and in SD - in Klebsiella pneumoniae mixes. For agents of wound infection especially in RITD, low species diversity was characteristic and the number of mixes variants is significantly higher. In RITD mixed infections develop more frequently, and the ecological community of microorganisms reaches higher values than in SD., Conclusion: During the analysis of microbiologi-cal data in RITD and SD general patterns and specific features of taxonomical structure, prevalence of mixed populations and character of their ecological community in wound infection was determined.

The growth and aroma contribution of Microbacterium foliorum, Proteus vulgaris and Psychrobacter sp., some common but rarely mentioned cheese bacteria, were investigated in a cheese model deacidified by Debaryomyces hansenii during the ripening process. Our results show that these bacteria had distinct growth and cheese flavour production patterns during the ripening process. P. vulgaris had the greatest capacity to produce not only the widest variety but also the highest quantities of volatile compounds with low olfactive thresholds, e.g. volatile sulphur compounds and branched-chain alcohols. Such compounds produced by P. vulgaris increased after 21 days of ripening and reached a maximum at 41 days. The three bacteria studied exhibited various degrees of caseinolytic, aminopeptidase and deaminase activities. Moreover, P. vulgaris had a greater capacity for hydrolysing casein and higher deaminase activity. Our results show that P. vulgaris, a Gram-negative bacterium naturally present on the surface of ripened cheeses, could produce high concentrations of flavour compounds from amino acid degradation during the ripening process. Its flavouring role in cheese cannot be neglected. Moreover, it could be a useful organism for producing natural flavours as dairy ingredients.

Between January 2002 and June 2007, uropathogens were isolated from 473 of 1557 canine urine samples submitted to Prairie Diagnostic Services from the Western College of Veterinary Medicine Veterinary Teaching Hospital. Culture and susceptibility results were analyzed, retrospectively, to estimate the prevalence of common bacterial uropathogens in dogs with urinary tract infections and to identify changes in antimicrobial resistance. The most common pathogens identified were Escherichia coli, Staphylococcus intermedius, Enterococcus spp., and Proteus spp. Antimicrobial resistance increased during the study period, particularly among recurrent E. coli isolates. Using the formula to help select rational antimicrobial therapy (FRAT), bacterial isolates were most likely to be susceptible to gentamicin, fluoroquinolones, amoxicillin-clavulanic acid, and groups 4 and 5 (third generation) cephalosporins.

Flavonoids from Pelargonium radula (Cav.) L'Hérit were purified by column chromatography. Two fractions were obtained: F1 (main flavonoid isoquercitrin) and F2 (main flavonoid rutin). In vitro antimicrobial activity of F1 and F2 were tested against eleven species of bacteria and eleven species of fungi. Both fractions demonstrated strong inhibitory activity against Staphylococcus aureus, Proteus rettgeri, Candida tropicalis and Microsporum gypseum. Staphylococcus sp. (coagulase-negative) and Candida lusitaniae were strongly inhibited only by fraction F1 and Fusarium graminearum only by fraction F2.

Bacteria contaminate the uterus of most dairy cattle after parturition and endometritis causes infertility. An endometritis score can be ascribed based on the vaginal mucus character and odour but it is not clear if the clinical score reflects the number of uterine bacteria or the inflammatory response. The present study tested the hypothesis that clinical evaluation of endometritis reflects the number of bacteria present in the uterus, and the acute phase protein response. Swabs (n = 328) were collected from the uterine lumen of dairy cattle, 21 and 28 days postpartum, vaginal mucus was scored for character and odour, and blood samples collected for acute phase protein measurement. Bacteria were identified following aerobic and anaerobic culture, and the bacterial growth density was scored semi-quantitatively. When bacteria were categorised by their expected pathogenic potential in the uterus, purulent or fetid odour vaginal mucus was associated with the growth density of pathogenic bacteria but not opportunist contaminants. When bacteria were analysed independently, Arcanobacterium pyogenes, Proteus and Fusobacterium necrophorum growth densities were associated with mucopurulent or purulent vaginal mucus. The bacterial growth densities for A. pyogenes, Escherichia coli, non-hemolytic Streptococci, and Mannheimia haemolytica were associated with a fetid mucus odour. Peripheral plasma concentrations of alpha(1)-acid glycoprotein were higher if there was a fetid compared with a normal vaginal mucus odour (1.50 +/- 0.09 mg/mL versus 1.05 +/- 0.02 mg/mL, P < 0.001), but did not differ significantly between vaginal mucus character scores. The evaluation of the character and odour of vaginal mucus reflects the number of bacteria in the uterus, and the acute phase protein response.

Antimicrobial activities of 10-100% (wt/vol) concentrations of new honey, stored honey, heated honey, ultraviolet-exposed honey, and heated stored honey were tested against common human pathogens, including Escherichia coli, Entrobacter cloacae, Pseudomonas aeruginosa, Shigella dysenteriae, Klebsiella sp., Haemophilus influenzae, Proteus sp., Staphylococcus aureus, Streptococcus hemolyticus group B, and Candida albicans. Antimicrobial activity of honey was tested in acidic, neutral, or alkaline media. These were compared with similar concentrations of glucose in nutrient broth. Surgical wounds were made on the dorsum of mice and infected with S. aureus or Klebsiella sp. The wounds were treated with local application of honey four times a day or appropriate antibiotics and compared with control values. Bacterial conjunctivitis due to E. coli, Proteus sp., S. aureus, Klebsiella sp., and P. aeruginosa was induced in rats. Conjunctival application of honey four times a day or appropriate antibiotics was used for treatment and compared with control values. Growth of all the isolates was completely inhibited by 30-100% honey concentrations. The most sensitive microbes were E. coli, P. aeruginosa, and H. influenzae. Glucose showed less antimicrobial activity than honey, and many microbes showed positive culture even in 100% glucose. Heating to 80 degrees C for 1 hour decreased antimicrobial activity of both new and stored honey. Storage of honey for 5 years decreased its antimicrobial activity, while ultraviolet light exposure increased its activity against some of the microorganisms. Antimicrobial activity of honey was stronger in acidic media than in neutral or alkaline media. Single doses of honey used to prepare the 60% concentration in nutrient broth were bacteriocidal for P. aeruginosa and bacteriostatic for S. aureus and Klebsiella sp. during certain periods. Local application of raw honey on infected wounds reduced redness, swelling, time for complete resolution of lesion, and time for eradication of bacterial infection due to S. aureus or Klebsiella sp. Its potency was comparable to that of local antibiotics. Honey application into infective conjunctivitis reduced redness, swelling, pus discharge, and time for eradication of bacterial infections due to all the isolates tested.

Bacteria highly resistant to mercury isolated from seawater and sediment samples were tested for growth in the presence of different heavy metals, pesticides, phenol, formaldehyde, formic acid, and trichloroethane to investigate their potential for growth in the presence of a variety of toxic xenobiotics. We hypothesized that bacteria resistant to high concentrations of mercury would have potential capacities to tolerate or possibly degrade a variety of toxic materials and thus would be important in environmental pollution bioremediation. The mercury-resistant bacteria were found to belong to Pseudomonas, Proteus, Xanthomonas, Alteromonas, Aeromonas, and Enterobacteriaceae. All these environmental bacterial strains tolerant to mercury used in this study were capable of growth at a far higher concentration (50 ppm) of mercury than previously reported. Likewise, their ability to grow in the presence of toxic xenobiotics, either singly or in combination, was superior to that of bacteria incapable of growth in media containing 5 ppm mercury. Plasmid-curing assays done in this study ascertained that resistance to mercury antibiotics, and toxic xenobiotics is mediated by chromosomally borne genes and/or transposable elements rather than by plasmids.

Phorate [O,O-diethyl-S-(ethylthio)methyl phosphoradiothioate] degrading bacteria were isolated from agricultural soil and characterized based on their morphological and biochemical characteristics. The selected isolates PS-1, PS-2 and PS-3 were presumptively identified as Rhizobium, Pseudomonas and Proteous species, respectively. The HPLC analysis of phorate in bioaugmented soil revealed its complete disappearance within 40 days. The degradation isotherms of the isolates PS-1, PS-2 and PS-3 suggested time-dependent disappearance of phorate following the first order rate kinetics at the corresponding rate constants of 0.04, 0.05 and 0.04 days-1. Besides, the isolates concurrently exhibited substantial phosphate solubilization, indole acetic acid, and siderophore production. The isolate PS-3 also showed anti-fungal activity against a phytopathogen Fusarium oxysporum. As a result of the multifarious biological properties, the isolates have been suggested to be important bioresource for efficient bioinoculant development.

A selective Proteeae medium (SPM) for isolation and preliminary detection of species of genera Proteus, Morganella, and Providencia was evaluated. The SPM contains tryptose phosphate agar with phenolphthalein monophosphate (as substrate for phosphatase activity), bile salts and polymyxin B (as inhibitors). The selectivity of the SPM was tested by the ecometric method of quality assurance of culture media. Fourteen reference cultures of enterobacteria and fifty-four strains of Proteeae were tested for their absolute growth index (AGI). Ninety-five percent of tested Proteeae strains display an AGI above 2.5. The detected phosphatase activity proved to be able to discriminate colonies of members of the tribe Proteeae. The ability of SPM for primary isolation of members of Proteeae was tested on food and clinical material and 94 strains were isolated. In addition, the SPM was employed in routine practice of clinical microbiology. From 1016 clinical samples (stool, urine, vaginal and urethral swabs), 57 strains of Proteeae were detected by the SPM in contrast to 35 strains by the routine procedure. The difference amounts to nearly 40%.

This study investigated the antibacterial activity of human pleural fluid (HPF) and its interaction with gentamicin (GM), meropenem (MRPM), ciprofloxacin (CPFX) and clarithromycin (CLTM) against Escherichia coli K-12, Proteus rettgeri (Sanelli) and Staphylococcus aureus. Minimal inhibitory concentrations or volumes, expressed as MIC or volume percentage (MIV, V/V%), were measured using a micro-dilution technique in microtiter plates. The antimicrobial activity of HPF combinations with antimicrobial drugs was evaluated by the chequerboard method calculating the fractional inhibitory concentration index (FIC) values. HPF MIVs (%) were: 37.54; 19.85; 1.74 for E. coli, P. rettgeri and S. aureus, respectively. FIC values indicated a synergistic effect with GM, MRPM and CPFX against E. coli and P. rettgeri and an additive effect for the combination HPF plus CLTM or indifference with HPF plus GM and CPFX against S. aureus. The presence of antibodies, complement factors, lysozyme, alpha-defensins and enzymes could explain the antimicrobial activity of HPF and its synergistic effect with certain antibiotics.

A novel bulk acoustic wave (BAW) bacterial growth biosensor was developed to study in vitro susceptibility by continuous monitoring of disturbances of bacterial growth at low antibiotic concentrations, followed by the accurate and rapid estimation of growth kinetic parameters and minimum inhibitory concentrations (MICs). The susceptibilities of bacteria, e.g. Escherichia coli, Staphylococcus aureus, Proteus vulgaris, Pr. morganii and Pr. mirabilis, to various antibiotics, e.g. penicillin, streptomycin, gentamicin and cefotaxime, were investigated, respectively, and the MICs were rapidly determined with a higher reproducibility than the conventional broth micro-dilution technique (BMDT). The effects of cell constant of conductivity electrode, pH and temperature on bacterial growth and biosensor signals were discussed in detail. The proposed method offers an effective alternative to the conventional methods.

A bulk acoustic wave (BAW) bacterial growth sensor has been proposed for study of inhibitory effects of tea by continuous monitoring of disturbances in Proteus growth in the aqueous extracts of various teas, e.g. green tea, Fuzhuan brick tea, Oolong tea, Kudin tea, and black tea. The kinetic parameters, e.g. asymptote (A), maximum specific growth rate (microm), lag time (lambda), and generation time (g), accurately estimated by using the growth response model, have been first used to characterize antimicrobial properties of tea. All of the parameters were changed via the inhibitory effects by tea. Green tea gives the weakest inhibitory action while others show stronger inhibitory actions. These inhibitory effects have also been examined by using the pour plate count technique. Both of the results show that, in addition to the antimicrobial properties of tea polyphenols and catechins, etc., the inhibitory effects may be attributed to the metabolites produced during the fermentation processing of these teas except green tea. The conventional disk diffusion test has been used to determine the minimum inhibitory concentration (MIC) against P. rettgeri. The MICs of green tea, Fuzhuan brick tea, Oolong tea, and black tea were found to be 1113, 818.0, 681.2, and 510.4 microg/mL, respectively. The BAW bacterial growth sensor has shown to have advantages over other techniques, including the disk diffusion test, photometry, and the impedance method.

Three Proteus species P. vulgaris, P. mirabilis and P. penneri have been characterized by repetitive sequence-based PCR. Four families of repetitive sequence based primers REP, ERIC, BOXA1R and BOXA2R, give specific patterns for each Proteus species. Species differentiation was best afforded using BOXA2R for detection of P. mirabilis, either REP-Dt or BOXA1R primers for detection of P. penneri and ERIC primer pair for P. vulgaris.

An acidic O-specific polysaccharide isolated from Proteus penneri 52 contains D-galacturonic acid, 2-acetamido-2-deoxy-D-glucose, and 2-acetamido-2-deoxy-D-galactose in the ratio 1:2:2. On the basis of sugar analysis and NMR spectroscopy, which included one-dimensional TOCSY, two-dimensional COSY, heteronuclear 13C, 1H-COSY, and rotating-frame NOE spectroscopy, the following structure of the pentasaccharide repeating unit of the O-specific polysaccharide was established: [sequence: see text] Cross-reactivity of the anti-P-penneri 52 O-serum with other strains of P. penneri isolated in Germany. Poland, USA, and Canada is discussed and a new Proteus serogroup is proposed.

Growth promotion and iron transport studies revealed that certain alpha-keto acids generated by amino acid deaminases, by enterobacteria of the Proteus-Providencia-Morganella group (of the tribe Proteeae), show significant siderophore activity. Their iron-binding properties were confirmed by the chrome azurol S assay and UV spectra. These compounds form ligand-to-metal charge transfer bands in the range of 400 to 500 nm. Additional absorption bands of the enolized ligands at 500 to 700 nm are responsible for color formation. Siderophore activity was most pronounced with alpha-keto acids possessing an aromatic or heteroaromatic side chain, like phenylpyruvic acid and indolylpyruvic acid, resulting from deamination of phenylalanine and tryptophan, respectively. In addition, alpha-keto acids possessing longer nonpolar side chains, like alpha-ketoisocaproic acid or alpha-ketoisovaleric acid and even alpha-ketoadipic acid, also showed siderophore activity which was absent or negligible with smaller alpha-keto acids or those possessing polar functional groups, like pyruvic acid, alpha-ketobutyric acid, or alpha-ketoglutaric acid. The fact that deaminase-negative enterobacteria, like Escherichia coli and Salmonella spp., could not utilize alpha-keto acids supports the view that specific iron-carboxylate transport systems have evolved in members of the tribe Proteeae and are designed to recognize ferric complexes of both alpha-hydroxy acids and alpha-keto acids, of which the latter can easily be generated by L-amino acid deaminases in an amino acid-rich medium. Exogenous siderophores, like ferric hydroxamates (ferrichromes) and ferric polycarboxylates (rhizoferrin and citrate), were also utilized by members of the tribe Proteeae.

Okpiye is a food condiment prepared by the fermentation of Prosopis africana seeds. The traditional process for the production and microbiological characteristics of the condiment were investigated. During laboratory fermentation that lasted 96 h, the mesquite seeds underwent a natural fermentation that was characterised by the growth of microorganisms to 10(6)-10(8) cfu/g. Several species of bacteria especially B. subtilis, B. licheniformis, B. megaterium, Staphylococcus epidermidis and Micrococcus spp were found to be the most actively involved organisms. However, significant contributions to the microbial ecology were made by Enterobacter cloacae and Klebsiella pneumoniae. Lactobacillus spp were present in low numbers towards the end of the fermentation. The presence of Proteus and Pseudomonas spp in traditional fermented samples demonstrate the variability which may exist in the microflora of individual fermented samples. Variations in the important microbial groups show that Bacillus spp were the most prevalent species and occurred until the end of fermentation. Temperature, pH and titratable acidity varied with time and were influenced by the metabolic activities of the microorganisms.

In this study the effect of selective intestinal decontamination of the digestive tract (SDD) on wound colonization was investigated. Ninety-one patients with at least 25 per cent total burned surface area (TBSA) were included in this study. All patients received oral polymyxin. In 63 patients oral co-trimoxazole and amphotericin B were added to the regimen. The addition of co-trimoxazole decreased the incidence of Enterobacteriaceae wound colonization from 71 per cent to 11 per cent (P less than 0.005). Colonization with Proteus was eliminated in patients treated with co-trimoxazole, compared with an incidence of 36 per cent in the group treated with polymyxin alone (P less than 0.001). The addition of amphotericin B decreased yeast colonization of the burn wound from 39 per cent to 10 per cent (P less than 0.005). A close relation was observed between burn wound colonization and colonization of the gastrointestinal tract. No resistant bacterial strains emerged during the period of study. These results suggest that SDD is an effective method for prevention of wound colonization. Further controlled studies are needed to establish the role of SDD in preventing burn wound colonization and wound sepsis.

A differential agar medium for the identification of Ureaplasma urealyticum in primary cultures of clinical specimens is described. The differential medium (no. A7) is specific for the identification of U. urealyticum and other members of the genus Ureaplasma. Large-colony, classical Mycoplasma and Acholeplasma species and Proteus L colonies are unreactive on this differential medium. The medium incorporates the biochemical principle of the direct spot test for urease in colonies of Ureaplasma and contains added urea and a sensitive indicator of ammonia, manganous sulfate. Ureaplasma colonies on this medium are identified as dark golden-brown or rich deep-brown colonies, in sharp contrast to the light background of the medium, when viewed by direct transmitted illumination under the low power of the microscope.

Stable small-colony variants of Proteus species were isolated and characterised. They differed from typical organisms in their morphology, biochemical properties and drug resistance. They were found most frequently in culture media of low osmolarity. Their growth rate was depressed at high concentrations of salts, which had only a small effect on typical organisms. This may be important in the routine isolation of proteus spp. and in testing of disinfectants.

A study on the mechanism of infection and the characterization of Malassezia pachydermatis in connection with canine otitis externa was conducted. The ability of this yeast to grow uninhibited in intimate contact with the diversity of other microbial isolants of the canine aural canal was demonstrated. Canine cerumen seemed to promote the growth of this yeast. Although the source of infection is still obscure, M. pachydermatis managed to survive in soil and dust at different temperatures for four weeks. Among the commonly used diagnostic media, Sabouraud's dextrose agar was shown to be the most supportive for the growth of this yeast.

A total of 100 strains of Proteus, clinically isolated, were tested for sensitivity to ovotransferrin and CrCl3. Only a minority of the tested strains were not capable of growing in the presence of these iron chelating substances. Significant differences in the resistance among the four species of Proteus were noticeable only by addition to the culture medium of CrCl3 5 mM. The fact that sensitive strains were capable of growing after addition of citrate to culture medium containing ovotransferrin or CrCl3 suggests the presence in the genus Proteus of a citrate-dependent iron transport system.

The Authors have tested in 3 isolating and enriching broths some Salmonellae; the broths are available commercially (MUELLER-KAUFMANN broth, LEIFSON broth and HAJNA GN broth) and they tested their inhibitory capacity (concerning the growth of intestinal saprophyte flora) and their enriching capacities with regard to the various types of Salmonellae also. The method used consists in an exact evaluation of the increase percentage of the germs which were put to incubate in the broths at 37 degree C for 6, 15 and 24 hours. On completing the tests it is clearly evident that the MUELLER-KAUFMANN and the LEIFSON broths are far superior to the HAJNA broth (which proved to be not very activated in decreasing the growth of the intestinal saprophytes). At the same time, it should be pointed out the opportuneness of effecting the re-transplantation from the Salmonellae broths only after 24 hours, in order to permit a more abundant growth of the Salmonellae (and therefore easier and surer isolation) without, at the same time, observing an appreciable interference by the common intestinal saprophytes.

Head-space gas-liquid chromatography and mass spectrometry were used to detect and identify products formed by Proteus vulgaris, P. mirabilis, P. morganii, and P. rettgeri from a defined medium supplemented with either phenylalanine, methionine, valine, leucine, histidine, lysine, ornithine, threonine, asparagine, aspartic acid, or tryptophan. In a detailed study of the products formed by 68 strains of Proteus spp. from L-methionine, the production of large amounts of both dimethyl disulfide and methyl mercaptan was found to be a characteristic of the genus. Both sulfur products appeared within a few hours of inoculation. Dimethyl disulfide was a more sensitive indicator of growth than the spectrometric determination of optical density. This suggests that it could be useful for the rapid, automated detection of any species of Proteus.

Catheter encrustation was studied in a group of long-stay hospital patients using both latex and silicone catheters. Moisture accounted for 80% by weight of the encrusted material with both catheters. Of the dry weight 90% was composed of protein, calcium, phosphorus, magnesium and uric acid. No relationship was found between the amounts of these substances in the urine and in the encrusted material. High levels of calcium, phosphorus and magnesium were found in the encrusted material from patients infected with Proteus organisms. No direct relationship was found between the duration of catheter drainage and the degree of encrustation, and there was a variation in patient susceptibility to encrustation irrespective of the catheter material. There was significantly less encrustation associated with silicone catheters.

All bacteria of the Morganella-Proteus-Providencia group tested produced a brownish pigment on agar containing L-forms of aromatic amino acids, i.e. histidine, phenylalanine, tryptophan, and tyrosine in the presence of iron ions under aerobic conditions. No pigment was observed without iron or when using D-forms of the amino acids. It is a melanin-like pigment with variable molecular weight under about 12000 D and an absorbance maximum between 330 and 410 nm depending on the concentration and the amino acid metabolized. Moreover, there is evidence that aldehydes are intermediates. In addition, the bacteria develop a characteristic almond-like smell on phenylalanine agar.

The metabolic activities of faecal and urinary strains of Proteus morgani and P. mirabilis were compared. Regardless of origin, the generation time of P. morgani strains in urine was approximately twice as long as that of the P. mirabilis strains. Urease synthesis was constitutive in P. morgani strains but required induction with urea in the P. mirabilis strains. In the presence of urea, the P. mirabilis strains liberated ammonia more rapidly and produced alkaline conditions more quickly than P. morgani strains, although they synthesized much less urease. These characteristics may place P. morgani strains at a disadvantage in comparison with P. mirabilis strains in their ability to cause urinary tract infections.

Wild-type Proteus strains are usually resistant to colistin. We have observed an increase in the level of colistin resistance in four clinical isolates of P. vulgaris, P. morganii, and P. rettgeri by prior treatment with subinhibitory concentrations of the drug. The enhanced resistance in these strains was lost after cultivating them in colistin-free medium, indicating that the enhanced resistance in the Proteus group is inducible.