Flavobacterium Research Articles

Impact of Trichoderma harzianum and bacterial strains against Striga hermonthica in Sorghum

A series of laboratory and green house experiments were conducted to investigate the efficacy of Trichoderma harzianum fungi, bacteria ( Flavobacterium, Bacillus megatherium var. phosphaticum (BMP) and Azomonas ) on Striga hermonthica early developmental stages , incidence and sorghum growth under laboratory and greenhouse conditions. The first laboratory experiment results showed that application of BMP + Flavobacterium significantly inhibited S. hermonthica seeds germination during and after conditioning in response to GR24 concentrations as compared to medium control. In the second laboratory experiment, application of the filtrate of T. harzianum alone or in combinations with bacteria significantly inhibited S. hermonthica germination and haustorium initiation as compared to the corresponding control. From greenhouse experiment results, S. hermonthica emergence significantly reduced by T. harzianum and insignificantly by the combination of Flavobacterium + BMP + T. harzianum . T. harzianum followed by the combination of Flavobacterium + BMP gave the highest increment in plant height. T. harzianum significantly increased sorghum number of leaves as compared to the infested control. The combination of Flavobacterium + BMP + T. harzianum gave the highest number of leaves. The combination Flavobacterium + BMP gave the highest sorghum shoot dry weight, followed by T. harzianum . While the highest sorghum root dry weight was obtained from the combination of Flavobacterium + BMP + T. harzianum . Generally, the combination of T. harzianum + Flavobacterium + BMP reduced S. hermonthica infestation and enhanced sorghum growth in comparison to the infested control.

Complete Genome Sequence of an Aquaculture-Associated Phage, FL-1, Infecting Flavobacterium spp.

ABSTRACTFL-1, a myophage of Flavobacterium, was found to have a 53-kb genome with 87 putative coding sequences.

ESTIMATION OF MICROBIAL BURDEN DUE TO DIFFUSED AND POINT SOURCES AT SPATIAL SCALE IN MIDDLE STRETCH OF RIVER BHAVANI, COIMBATORE, TAMILNADU

This study was aimed to estimate the microbiological status of river Bhavani which is the major life line of the surrounding area. The river water is used mainly for drinking, washing and swimming purposes. Water samples were collected from five sites (Pilloor, Effluent, Sweage I & II, Bhavanisagar reservoir) and theresults obtained were compared with WHO and EP standards for drinking and recreational water. In the present investigation station III and IV (which is Sweage I & II respective points) showed more numbers of microbes were present which cause the deadly diseases to human being as well as in aquatic, terrestrialorganism due the sewage discharges from the nearby towns. But in the case of lower stream (Bhavanisagar reservoir) that the counts of microorganism present in the reservoir was slightly reduced. The major groups of microorganisms were isolated and identified are E. coli, P. aerugionosa, E. aerogenes, S. aureus, Salmonella sp, Bacillus sp, Proteus sp, Klebsiella sp, Flavo bacterium, Acinetobacter sp. The results are alarming and show that alternative measures to reduce the pollution should be taken in favor of society

Epidemiological investigation on respiratory diseases in 1 300 children, in Jinan, Shandong

To analyze the characteristics of respiratory diseases and to provide scientific basis for developing relevant control measures. 1 300 children with respiratory diseases were treated in hospitals, from Jan. 2013 to May 2014, in the city of Jinan. Characteristics of respiratory diseases were analyzed. The distribution of respiratory diseases in children appeared as: 373 cases of pneumonia (28.7%), 3 cases of pulmonary tuberculosis (0.2%), 467 cases of acute bronchitis (35.9%), 102 cases of asthma (7.8%), and 355 cases of upper respiratory tract infection (27.3%). The upper respiratory tract infection contained 168 cases of tonsillitis (12.9%), 91 cases of pharyngitis (7.0%), 52 cases of laryngitis(4.0%)and 44 cases of iaryngopharyngitis (3.4%). The age distribution of cases with children respiratory diseases appeared as:71 cases <1 years old (5.5%), 385 cases as 1-2 years old (29.6%), 534 cases as 3-6 years old (41.1%), 258 cases as 7-12 years old (19.8%)and 52 cases as >13 years old (4.0%). The seasonal distribution of children respiratory diseases appeared as:364 cases in Spring (28.0% ), 163 cases in summer (12.5%), 315 cases in autumn (24.2%)and 458 cases in winter (35.2%). Regional distribution of children respiratory diseases appeared as:516 cases in urban area (39.7%), 225 cases in suburb (17.3%), 376 cases in townships (28.9%)and 183 in villages (14.1%). 725 strains were isolated and identified that containing 349 strains(48.1%) of Mycoplasma pneumoniae, 136 strains (18.8%) of Haemophilus influenza, 103 strains (14.2% ) of Streptococcus pneumoniae, 82 strains (11.3% ) of Klebsiella pneumoniae, 38 strains (5.2%) of Acinetobacter baumannii, 35 strains(4.8%) of Enterobacter cloacae, 22 strains (3.0%) of Streptococcus pyogenes, 17 strains (2.3%) of Alcaligenes, 16 strains (2.2% of Candida albicans)and 9 strains (1.2%) of Flavobacterium indologenes. 1 288 cases (99.1%) were cured. The common respiratory diseases would include bronchiolitis, pneumonia and upper respiratory tract infections in children, mostly attacking 3-6 year-olds at preschool stage, with spring, winter, urban and township as the prevalent seasons and areas.

Plant growth promoting activities of rhizobacteria associated with tomato in semi-arid region

The present investigation was designed to evaluate the plant growth promoting activities of rhizobacteria associated with tomato. Twenty six rhizosphere soil samples of tomato were randomly collected from tomato cultivating areas of district Faridabad, Haryana, India and a total of 56 strains of rhizobacteria were isolated on three different selective and non-selective medium i.e. nutrient agar, King’s B agar and glycerol-arginine agar at 300C. Pseudomonas was identified as the predominant bacterial genus with almost 34% of the isolated strains belonging to this genus. All isolated strains were evaluated for indole acetic acid (IAA) production and phosphate solubilization. In vitro IAA production was observed in 76.8% isolates and phosphate solubilizing activity was given by 41.1% isolates. Isolates varied significantly (P < 0.05) for IAA production as well as phosphate solubilization. The average IAA concentration recorded for these isolates was 6.32 μg/ml and the inorganic phosphate (Pi) released in Pikovskaya’s broth at 15 days after incubation (DAI) was 18.80 μg/ml. The average pH of Pikovskaya’s broth at fifteen DAI dropped to 5.20 from 7.00 at 0 DAI. Leading IAA producing genera were Flavobacterium and Azotobacter while maximum P-solubilization activity was shown by the genus Pseudomonas. The isolate TNAM22 gave the highest IAA concentration of 9.81 μg/ml while the isolate TKB14 released maximum Pi i.e. 22.7 μg/ml.

Surveillance of the condition of bacteria and Amaranthus viridis in a gasoline contaminated soil

The condition of bacteria and Amaranthus viridis in gasoline-contaminated soil was surveyed. The soil was treated with different concentrations of petrol oil: 0 ml (control), 18, 56, 112, 168 and 224 ml. Each of the concentrations was in triplicates. Seventeen (17) bacterial isolates were recovered from the control soil while twenty (20) bacterial isolates were recovered from the polluted soil. A total of twenty four (24) different genera were recovered from the soil. The organisms areAcinetobacter ceticus, Actinomyces sp, Aerococcus viridians, Alcaligenes paradoxus, Arthrobacter, Bacillus cereus, Bacillus polymxa, Bacillus subtilis, Chromobacterium violaceum, Clostridium sp., Corynebacterium hydrocarbodastus, Corynebacterium kutsceri, Corynebacterium xerosis, Cytophaga sp., Erwinia sp., Flavobacterium sp., Micrococcus luteus, Proteus vulgaris, Pseudomonas fluorescens, Pseudomonas putida, Sarcina ventricule, Serratia sp., Staphylococcus aureus, and Streptococcus sp. The pH, temperature, organic matter content, moisture content and water holding capacity of the soil were determined. A. viridis had 100% germination in both the control (0 ml) and 18 ml gasoline-treated soils while it had delayed germination in the other treatments (56, 112, 168 and 224 ml). The results obtained in this study showed that gasoline spillage posses a great threat to the survival and development of plants. It also revealed that certain bacteria could survive the gasoline-contaminated soil and thus may be useful in biodegradation and/or bioremediation of gasoline contaminated soils. Key words: Surveillance, bacteria, Amaranthus viridis, gasoline, contaminated soil.

Retrospective studies of the trends of occurrence of ruminant mastitis pathogens in a veterinary teaching hospital in Northwest, Nigeria

A retrospective study to determine the pattern of isolation of mastitis causing organisms from milk samples of cattle, sheep and goats submitted to the Microbiology laboratory of the Department of Veterinary Pathology and Microbiology Ahmadu Bello University Zaria from 1980-1991 and 1999-2009 was conducted . The samples were subjected to cultural isolation and biochemical characterization. The results of the isolates were assembled, reviewed and summarised. A total of 227 milk samples were submitted from cattle (40), sheep (31) and goats (156) respectively, from the years 1980 to 1991 and 1999 to 2009 and subjected to cultural isolation and biochemical characterization. A total of 18 different organisms were isolated from 158 of the samples submitted. Six of the submitted samples were un-typeable while 63 were culture negative i.e showed no growth. The most commonly isolated mastitis causing organisms from all samples were: Staphylococcus aureus (26.51%), Escherichia coli (12.20%), Staphylococcus spp (10.24%), Streptococcus spp (6.63%) and Corynebacterium spp (7.32%). Other organisms are , Micrococcus (1.22%), α-hemolytic Streptococcus (1.83%), β- haemolytic Streptococcus (2.42%), Pseudomonas aeroginosa (4.88%), Enterobacter spp (1.83%), Proteus spp (4.89%), Lactobacillus spp (2.42%), Pasteurella spp (4.27%), Klebsiella spp (3.05%), Citrobacter spp (0.61%), Candida albican (0.61%), Flavobacterium spp (0.61%), Bacillus spp (3.67%), Acinetobacter spp (1.20%) and Sarcina spp (0.61%). Staphylococcus aureus was the most predominant organism isolated from cattle, sheep and goat milk. There was a significant reduction in occurrence of mastitis from 201 (88.55%) cases within 1980-1991 and 26 (11.45%) cases within 1999-2009.

The effect of high total ammonia concentration on the survival of channel catfish experimentally infected with Flavobacterium columnare.

Ammonia concentrations in water can affect the severity of Flavobacterium columnare infections in fish. Two trials lasting 7 d each were conducted to determine the effect of a single immersion flush treatment of total ammonia nitrogen (TAN; 15 mg/L) on the survival of channel catfish Ictalurus punctatus infected with E columnare; the chemical was added while the water flowed continuously through the tanks. Both trials consisted of four treatments: (1) no ammonia exposure and no bacterial challenge (control), (2) ammonia exposure only, (3) bacterial challenge only, and (4) both ammonia exposure and bacterial challenge. Two hours after exposure to ammonia, the highest un-ionized ammonia level was 0.43 mg/L. The percent un-ionized ammonia is based on TAN, temperature, and pH. Caudal fins from three fish in each treatment were sampled at 24 h posttreatment to be analyzed by quantitative real-time polymerase chain reaction (qPCR). No significant difference in survival (mean +/- SE) was noted between the channel catfish in treatment 1 (95.2 +/- 1.2%) and those in treatment 2 (95.6 +/- 1.0%); however, survival in both treatments 1 and 2 differed significantly from that in treatments 3 (8.5 + 4.5%) and 4 (41.8 +/- 12.7%). Treatment 4 catfish had significantly higher survival than treatment 3 catfish. Quantitative PCR data showed that treatment 4 fish had significantly less F. columnare (7.6 x 10(5)) than did treatment 3 fish (1.2 x 10(7)), and treatment 2 fish (8.5 x 10(3)) had significantly less bacteria than did treatment 1 fish (6.9 x 10(4)), indicating that ammonia limited the F. columnare infection. The highest mean concentration of the bacteria (3.9 x 10(7)) was found on moribund fish. The ammonia concentrations tested did not negatively influence fish survival but interfered with the infection process. An in vitro assay was also conducted to evaluate the direct effects of ammonia on F columnare.

Fungal and bacterial contaminants of six spices and spice products in Ghana

The microbiological quality of two spices (aniseed and rosemary) and spice products (maggi onion cube, maggi shrimp cube, royco shrimp cube, royco beef cube) have been studied using conventional mycological techniques. The presence of moulds and yeast was compared on three media DRBC, OGYE, and PDA at 30°C incubated for 5 days. The species of fungi that were isolated from the raw spices and spice products tested belonged to eight (8) genera. (Absidia, Aspergillus, Cladosporium, Fusarium, Rhizopus, Penicillium, Neurospora, Eurotium,). Aspergillus species (A. flavus, A. fumigatus, A. alutaceus, A. niger, A. sulphureus) were the more predominant species isolated. A. flavus was the most frequently isolated fungal species in all the spices on all the three media on which growth was compared. Aniseed harboured fungal population ranging from 1.50 log10 CFU/g sample to 1.88 log10 sample; maggi onion cube 0.90 – 1.54 log10 CFU/g sample; maggi shrimp cube 1.11 – 1.30 log10 CFU/g sample; royco shrimp cube; 1.0 – 1.08 log10 CFU/g sample and 1.19 – 1.31 log10 CFU/g sample in royco beef cube. The aflatoxin analysis showed that aflatoxins B1 , B2, G1,and G2 were not formed. The bacteria species isolated from the spices varied. The spices and spice products collectively harboured Aeromonas salmonicida, Enterobacter cloacae, Enterobacter amnigenus, Enterobacter agglomerans, Enterobacter sakazakii, Flavobacterium sp, Chromobacterium violaceum, Pseudomonas putida, Pseudomonas aeroginosa, Acinetobacter sp, Pseudomonas cepacia, Serratia plymuthica. The human health implications of these findings are discussed and future work recommended. Key words: Microbiological quality, spices, spice products, contaminants

Evaluation of Mycobacterium kansasii isolates from a clinical laboratory in a city hospital

Fifteen isolates of Mycobacterium kansasii in Showa University Fujigaoka Hospital between 1982 and 1995 were investigated. Comparing by gender, 13 were isolated from male patients and only two were isolated from female patients. The average of cases was 48 years old and 14 out of 15 cases (93%) were isolated from respiratory tract specimens. The rate of the smear- and culture-positives was 64%, which was significantly higher than that (26%) of M. avium complex (p < 0.01 by chi 2 test). All 4 isolates were susceptible to rifampicin (10 micrograms/ml) by drug susceptibility testing using Ogawa egg medium, and only 1 was resistant to ethambutol (2.5 micrograms/ml). Seven out of 10 patients whose medical record was available were diagnosed as pulmonary infection with M. kansasii. Two out of 4 patients with primary infection type had underlying diseases such as diabetes mellitus and leukemia, while the remaining two patients did not have any underlying disease. Two out of 3 patients with secondary infection type had a medical history of tuberculosis and the remaining 1 patient had infected pulmonary cyst. Such as Pseudomonas aeruginosa, Enterobacter aerogenes and Flavobacterium spp., and Branhamella catarrhalis, associated with M. kansasii, bacteria more than 10(7) cfu/ml were isolated from the sputa of 3 patients with leukemia, infected pulmonary cyst and post-tuberculosis, respectively. M. kansasii, Stenotrophomonas maltophilia (10(7) cfu/ml) and Candida albicans were detected from the sputum of 1 patient with nephrosis, for which steroid (predonin) and antibiotics (piperacillin and latamoxef) were administrated, however, this patient was not diagnosed as a case of M. kansasii infection. These findings suggest the fact that M. kansasii inhabits among compromised hosts of a city hospital.

THE SINGLE EFFECT OF MICROBE ON THE CORROSION BEHAVIORS OF 25 STEEL IN SEAWATER

Biological elements have a significant impact on lifetime prediction of marine carbon steel facilities.Microbe can produce pitting,crevice corrosion,selective dealloying and stress-oriented hydrogen-induced cracking,which accelerate both localized and average corrosion rates of carbon steel. The formation of microbe films can also reduce the corrosion rate of 25 steel through inhibition of oxygen diffusion and depletion of oxygen in the electrolyte and metal/solution interface.The research on the single effect of microbe on the corrosion behaviors of metal is insufficient up to now.In this work,the single effect of microbe on the corrosion behaviors of 25 steel was studied by comparing the corrosion behaviors of the carbon steel in natural seawater and in sterile seawater.The results show that in most of immerging periods,the bacterial activity at the interface accelerated the average corrosion rate of 25 steel.When the corrosion time was 365 d,the average corrosion rate of 25 steel immersed in natural seawater was 2.6 times that in sterile seawater.However,when the corrosion time was 28 d,the biofilms inhibited the corrosion of 25 steel.The species and contents of microbes significantly influenced the corrosion behavior of 25 steel.The microbes in the corrosion product mainly consisted of pseudomonas,vibrio,crenothrixandleptothrix,thiobacillus and sulfate-reducing bacteria.When the corrosion time was 365 d,flavobacterium also existed in the corrosion product.The contents of aerobe,facultative anaerobe and anaerobe reached the maximum value when the corrosion time was 28,91 and 184 d,respectively.The regular change of the contents of microbes with the immerging time led to the different microbe corrosion mechanisms of 25 steel.

Spreading versus biomass production by colonies of the fish pathogen Flavobacterium psychrophilum: role of the nutrient concentration.

Colonies of the fish pathogen Flavobacterium psychrophilum have gliding motility in media with low agar concentrations. Although gliding motility, particularly in Flavobacterium johnsoniae, has been well-studied, little is known about its regulation by environmental factors. The work described here shows that the ability of F. psychrophilum to spread over surfaces depends on nutrient availability. In fact, as the nutrient contents of the medium decreased, spreading was favored and the diameter of the colonies increased. Macroscopy examination revealed modifications in colony morphology as nutrient depletion increased: from a dense and defined colony to the formation of microcolonies inside a general colony structure. Additionally, colony expansion dynamics and population density across the colony radius varied inversely with bacterial biomass production. Motility was an immediate response when bacteria were transferred from a rich to a more diluted medium. Our results suggest that, when nutrients are limiting, F. psychrophilum activates a specific growth mode that enables it to colonize surfaces by means of gliding motility. The use of diluted media allowed the differentiation, among previously isolated F. psychrophilum non-gliding mutants, of those completely unable to glide and those with only partially impaired gliding ability.

Microbiological and physicochemical analysis of different water samples used for domestic purposes in Abeokuta and Ojota, Lagos State, Nigeria

Samples of tap, well, stream, and wastewaters were collected from Abeokuta and Ojota (both in Nigeria) state and analyzed microbiologically and physico-chemically using standard methods. Total viable count was by pour plate technique while most probable number (MPN) counts were by the multiple tube fermentation technique. The pH (at 25oC) ranged from 3.10 to 8.33 for the untreated raw water samples while temperature ranged from 28 to 30oC while the turbidity of the water and waste water samples ranges from 0.08 to 1.00. All the water samples were found to harbor coliforms organisms in numbers greater than the required WHO/FAO standards for water. The total viable counts for all the water samples were generally high exceeding the limit of 1.0 x 102 cfu/ml for water. The MPN count ranges from 9.3 to 44 MPN/100 ml. The fecal coliform counts on EMB agar plate ranged between 5 and 48 cells, also exceeding the standard limit for water. The Isolated organisms were identified to be Staphylococcus aureus, Salmonellaspecies, Escherchia coli, Pseudomonas aerugionosa, Enterobacter aerogenes, Bacillus species, Proteus species, Klebsiella species, Flavobacterium species and Acinetobacter species. Key words: Microbiological analysis, standard methods, water, WHO/FAO.

Bacteriological water quality of Elechi creek in Port Harcourt, Nigeria

The bacteriological quality of Elechi creek was investigated during a seven-month sampling period. Samples were collected from seven stations grouped into zones A, B and C. The study revealed uniformity in the range of temperatures (which ranged from 28° to 32°C) in all the stations of the zones. The pH values obtained for all the stations ranged from 6.5 to 7.7 and were within the acceptable ranges for brackish water such as the study area. The BOD values for stations of zone B ranged from 3.92 to 8.80mg l-1 while those of zones A and C ranged from 2.07 to 3.86 mgl -1 and 1.43 to 3.46 mgl -1 respectively. The reverse was the case for DO values, which were lower in stations of zones B than those of zones A and C. The results for oil and grease values for all the stations of the zones showed a range of 0.09 to 1.22 ppm which were far lower than the permissible limit for industrial effluent samples. The minimal values suggested absence of petroleum activities in the area. The results of the bacterial counts for the Elechi creek showed that total aerobic heterotrophic bacteria ranged from 0.12 x 10 6 to 2.81 x 10 6 cfuml -1 , total coliform bacteria ranged from 0.06 x 105 to 2.00 x 105 cfuml -1 and hydrocarbon-utilizing bacteria ranged from 2.0 x 10 2 to 10.0 x 10 2 cfuml -1 . The bacterial genera isolated from the Elechi creek included Aeromonas, Bacillus, Citrobacter, Corynebacterium, Pseudomonas, Enterobacter, Escherichia, Flavobacterium, Klebsiella, Micrococcus, Proteus, Staphylococcus, Enterococcus , and Vibrio species. Of the organisms isolated only Bacillus, Corynebacterium, Pseudomonas and Flavobacterium species occurred in all the stations of the zones while the others occurred in one or more stations and not in others station. The varying mean counts of bacteria and the occurrence of bacterial species the creek, brought to consideration, the possible influence and sources of contamination around each zone. The observed high coliform counts and the presence of Escherichia coli was sufficient to suspect the contamination of the water body with pathogenic bacteria; hence the water is of low quality and should not be used for human consumption. The low counts of hydrocarbon-utilizing bacteria confirmed absence of a possible source of contamination of the creek by crude oil and its products. Journal of Applied Sciences and Environmental Management Vol. 9(1) 2005: 79-84

Catabolic and Genetic Diversity of Degradative Bacteria from Fuel-Hydrocarbon Contaminated Aquifers.

A BSTRACTSubsurface sediments were recovered from two aquifers contaminated with petroleum hydrocarbons in order to isolate and characterize indigenous microorganisms capable of biodegrading fuel-related compounds. These sediments had been previously studied using catabolic gene probes providing putative demonstration of significant biodegradation potential. Based on 16S rDNA sequence analysis, the isolates were phylogenetically similar to common soil microorganisms, including members of the genera Pseudomonas, Ralstonia, Burkholderia, Sphingomonas, Flavobacterium, and Bacillus. A total of 26 isolates were obtained using a vapor-plate enrichment technique with the volatile aromatic hydrocarbons toluene, ethylbenzene, p-xylene, naphthalene, and JP-4 jet fuel. JP-4, toluene, and ethylbenzene served as growth substrates for more than 80% of the isolates, while less than 10% of the organisms grew on the aromatic compounds benzene and o-xylene. Subsequent assays monitoring the evolution of (14)CO(2) indicated that only seven isolates were able to completely mineralize target compounds. One isolate, designated CAFB-naph-5, was able to completely mineralize the monoaromatic compounds salicylate and toluene, as well as the polyaromatic compound naphthalene. Molecular probing of the isolates showed four isolates hybridized with DNA probes targeting genes commonly associated with hydrocarbon-degrading bacteria. The isolates also demonstrated broad ability to grow in the presence of the antimicrobial agents streptomycin, tetracycline rifampicin, carbenicillin, nalidixic acid, kanamycin, and ampicillin. The results of the study demonstrate the biochemical and biodegradative capabilities of microorganisms isolated from contaminated aquifer systems and provide closure for indirect molecular monitoring of degradative potential in contaminated environments.

Quality of Ghana herbal tea: microflora and control measures

The microflora of Ghanaian herbal tea comprising dried leaves of Cinnamon, Hibiscus and Citronella have been investigated under field and laboratory conditions. Fungal species isolated varied from one sample to another. Sixteen fungal species were isolated from Hibiscus, belonging to the genera Aspergillus, Cladosporium, Eurotium, Manoascus. Paecilomyces, Penicillium, Septodochium, Rhizopus and Syncephalastrum; thirteen fungal species belonging to the genera Aspergillus, Cladosporium, Emericella, Monoascus, Penicillium, Streptomyces, and Rhizopus were resident in Cinnamon tea while nine fungal species belonging to the genera Aspergillus, Cladosporium, Monoascus, Rhizopus and Syncephalastrum were encounted on Citronella tea. Aspergillus species (A. candidus, A. fumigatus, A. ochraceus, A. rubrum, A. terreus, A. wentii) predominated followed by Cladosporium (C. herbarium, C. cladosporioides, C. macrocarpon). Some potential pathogenic bacteria (Flavobacterium meningoseptium, Pseudomonas cepacia, P. paucimobolis and Xanthomonas maltophila were also encountered. Some of the aeromycoflora isolated from the farms from which the tea leaves were harvested (Aspergillus candidus, A. fumigatus, A. ochraceus, Cladosporium clasosporioides, C. herbarium, Penicillium digitatum, Syncephalastrum spp.) also infected the dry leaf samples. Gamma irradiation up to 5.0 KGy reduced the microbiological loads of the tea samples by 2-5 log cycles. A combination of low (£ 75% ERH) storage ERH and packaging material (brown paper and transparent polyphone) significantly lowered the moisture content of the dried tea samples and increased their shelf life. Practical implication of these findings are discussed and further studies suggested. JOURNAL OF THE GHANA SCIENCE ASSOCIATION Volume 1 Number 3, July (1999) pp. 84-99

Flavobacterium Meningosepticumin Intensive Care Units of a Teaching Hospital in Riyadh, Saudi Arabia

<i>Flavobacterium Meningosepticum</i>in Intensive Care Units of a Teaching Hospital in Riyadh, Saudi Arabia

Factors affecting the survival of a FLavo bacterium species in non-planted and rhizosphere soil

Factors affecting the survival of a Gram-negative soil Flavobacterium sp. (P25) were investigated in small-scale laboratory microcosms. Two terms for expressing P25 persistence are used: survival—describing the number of P25 reisolated from soil at a certain time point; and survival rate—expressed as the time in days taken for a 90% (t90), 99% (t99) or 99.9% (t99.9) decline in numbers of P25. Survival rates of P25 increased in rhizosphere as opposed to bulk soil and were increased further by applying the inoculum directly to the planted seedling (t99 = 21 d) rather than homogenizing it through the soil prior to planting (t99= 10.5d). Survival was increased by using greater inoculum densities, for example following inoculation at 1,1 × 10 9P25 g −1soil, numbers surviving at day 40 were 12.5-fold greater than that achieved with 1.1 × 10 4 P25 g −1 In addition, survival rates of P25 were increased by applying the inoculant to soil at moisture holding capacities (MHC) between 40 and 50% (t99.9 = 12.2 d) in comparison to either wetter (e.g. 100% MHC, t99.9 = 3.5 d) or drier (e.g. 10% MHC, t99.9 = 1 d) soils. Carbon amendments (i.e. galactose, maltose, sorbitol) significantly increased survival of P25 in non-planted soil throughout the 35 d study whereas in rhizosphere soil an increase was only recorded for the first 14 d.

Root colonization by a Flavo bacterium species and the influence of percolating water

The colonization of wheat roots by Flavobacterium P25 was investigated in small scale microcosms. It was shown that, although P25 is a non-motile bacterium, cells applied to the germinating seed moved with the expanding root in the absence of downward water flow, and that the rate of movement kept pace with the growing root tip in both sterilized sand and non-sterile soil. Movement in soil did not increase with increasing water content and, in fact, the inoculant spread further and survived in higher numbers in the treatment at the lowest water content tested (50% MHC; −52 kPa). However, percolating water resulted in distribution of the bacterium throughout the soil column and to its appearance in the leachate after a single water addition. Introducing P25 into soil 1 week prior to the first water addition significantly reduced the percentage of the inoculant leached (5 vs 38%). The presence of P25 in the soil through which roots were growing did not increase the numbers of P25 on the root. However, by the final sampling date ( t = 30 days), P25 populations on lower root sections were greater (95 × at 8–12cm, 389 × at 12–16cm and 17.9 × at 16–20 cm) in percolated columns.

Evaluation of minocycline and cefuzonam for antimicrobial activity against clinical isolates.

The Antibacterial activity of minocycline (MINO) and that of cefuzonam (CZON) were assessed with clinical isolates of 19 species, and compared with that of other antibiotics. MINO was highly active against methicilli-sensitive Staphylococcus aureus (MSSA), Neisseria gonorrhoeae, Moraxella (Branhamella) catarrhalis, Haemophilus influenzae, Helicobacter pylori, Flavobacterium meningosepticum, Acinetobacter calcoaceticus, Peptostreptococcus spp. and Propionibacterium acnes, but not as effective against methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas cepacia and Alcaligenes xylosoxidans. CZON was highly active against MSSA, Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus pneumoniae, N. Gonorrhoeae, M(B). catarrhalis, H. influenzae, H. pylori, P. mirabilis, Peptostreptococcus spp. and P. acnes, but not effective against MRSA. It was minimally active against Gram-negative rods (E. coli, K. pneumoniae, etc.) and bacteria that do not ferment glucose.