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PubMed2000

Evaluation of antimicrobial treatment in mechanically ventilated patients with severe chronic obstructive pulmonary disease exacerbations.

OBJECTIVE: To study microbial and susceptibility patterns and antimicrobial treatment responses in patients with severe, acute exacerbations of chronic obstructive pulmonary disease requiring mechanical ventilation. DESIGN: Microbial investigation using tracheobronchial aspirates, bronchoscopy with a protected specimen brush, and bronchoalveolar lavage, as well as paired serologies. Evaluation of antimicrobial treatment by results of the initial investigation, susceptibility testing, and a repeated microbial investigation (tracheobronchial aspirates, bronchoscopy with a protected specimen brush, and bronchoalveolar lavage) after 72 hrs. SETTING: A respiratory intensive care unit of a 1,000-bed teaching hospital. PATIENTS: Fifty severely exacerbated and mechanically ventilated patients with chronic obstructive pulmonary disease. INTERVENTIONS: Initial empirical antimicrobial treatment according to clinical judgment. MEASUREMENTS AND MAIN RESULTS: Overall, 36 of 50 patients (72%) had evidence of a microbial origin. Community-acquired endogenous pathogens were present in 70% of patients, and Gram-negative enteric bacilli and Pseudomonas/Stenotrophomonas species were present in 30%. All five isolates of Streptococcus pneumoniae were resistant to penicillin (three intermediately and two highly), and three were resistant to multiple antibiotics. Pseudomonas species revealed multiresistance in four of nine isolates (44%), and Stenotrophomonas maltophilia revealed multiresistance in one of two isolates. Antimicrobial treatment was modified according to diagnostic results in 11 of 31 patients (36%) with potentially pathogenic microorganisms. In patients who underwent a repeat investigation after 72 hrs, 24% of the initially present and potentially pathogenic microorganisms persisted. Inappropriate initial antimicrobial therapy was associated significantly with bacterial persistence (p < .002). CONCLUSIONS: Considering the diversity of microbial pathogens and the resistance rates especially to S. pneumoniae in this patient population, antimicrobial treatment should be based on the constant study of local microbial and susceptibility patterns along with routine microbial investigation of the individual patient.

Aged↗
PubMed1996

Investigation of microbial keratitis: an audit from 1988-1992.

An audit was performed of the investigation of 263 cases of microbial keratitis severe enough to be admitted to the Manchester Royal Eye Hospital over the 5-year period, 1988-1992. A pathogen isolation rate of 37% was noted during the first year which increased to 79% (p < 0.05) by the final year of audit. In late 1991 a new method of inoculating enrichment broths was introduced, which also contributed by increasing the yield from corneal scrapes. The audit process resulted in the development of and adherence to our investigation protocol, improved communication between Manchester Royal Eye Hospital and the microbiology laboratory, the implementation of a new investigatory method, and a significantly improved microbial isolation rate.

Adolescent↗
PubMed2004

Oral bacteria and clinical variables in dependent individuals at a special facility.

The oral health of dependent residents at special facilities has often been reported as being poor, but it is difficult to relate oral health to general health and define the need for oral health care. Microbiological analyses of the oral flora have been suggested as a suitable method for evaluating oral health in this group of patients. A study was performed at a nursing facility where 33 individuals participated. The aim was to describe their oral flora in relation to other health variables and to classify the residents on different risk levels. An oral examination of the residents was made at the facility, together with a 3-day food record and an oral microbiological analysis. The analysis classified the residents in different categories according to both acid-producing bacteria and the flora correlated with a reduction in general health. The categories were based on previous studies conducted at the Department of Microbiology (Faculty of Odontology in Göteborg). The present study revealed that the level for acid-producing bacteria was high in 12 individuals and the micriobial level according to decreased general health was high in seven individuals. A high level of acid-producing bacteria was related to functional impairment, which was in turn related to nutritional problems and help with oral hygiene. The microbial level according to the reduction in general health did not significantly correlate with other variables.

Adult↗
PubMed1999

Effect of phenylurea herbicides on soil microbial communities estimated by analysis of 16S rRNA gene fingerprints and community-level physiological profiles.

The effect of three phenyl urea herbicides (diuron, linuron, and chlorotoluron) on soil microbial communities was studied by using soil samples with a 10-year history of treatment. Denaturing gradient gel electrophoresis (DGGE) was used for the analysis of 16S rRNA genes (16S rDNA). The degree of similarity between the 16S rDNA profiles of the communities was quantified by numerically analysing the DGGE band patterns. Similarity dendrograms showed that the microbial community structures of the herbicide-treated and nontreated soils were significantly different. Moreover, the bacterial diversity seemed to decrease in soils treated with urea herbicides, and sequence determination of several DGGE fragments showed that the most affected species in the soils treated with diuron and linuron belonged to an uncultivated bacterial group. As well as the 16S rDNA fingerprints, the substrate utilization patterns of the microbial communities were compared. Principal-component analysis performed on BIOLOG data showed that the functional abilities of the soil microbial communities were altered by the application of the herbicides. In addition, enrichment cultures of the different soils in medium with the urea herbicides as the sole carbon and nitrogen source showed that there was no difference between treated and nontreated soil in the rate of transformation of diuron and chlorotoluron but that there was a strong difference in the case of linuron. In the enrichment cultures with linuron-treated soil, linuron disappeared completely after 1 week whereas no significant transformation was observed in cultures inoculated with nontreated soil even after 4 weeks. In conclusion, this study showed that both the structure and metabolic potential of soil microbial communities were clearly affected by a long-term application of urea herbicides.

Bacteria↗
PubMed2003

Members of a readily enriched beta-proteobacterial clade are common in surface waters of a humic lake.

Humic lakes are systems often characterized by irregular high input of dissolved organic carbon (DOC) from the catchment. We hypothesized that specific bacterial groups which rapidly respond to changes in DOC availability might form large populations in such habitats. Seasonal changes of microbial community composition were studied in two compartments of an artificially divided bog lake with contrasting DOC inputs. These changes were compared to community shifts induced during short-term enrichment experiments. Inocula from the two compartments were diluted 1:10 into water from the more DOC-rich compartment, and inorganic nutrients were added to avoid microbial N and P limitation. The dilutions were incubated for a period of 2 weeks. The microbial assemblages were analyzed by cloning and sequencing of 16S rRNA genes and by fluorescence in situ hybridization with specific oligonucleotide probes. beta-Proteobacteria from a cosmopolitan freshwater lineage related to Polynucleobacter necessarius (beta II) were rapidly enriched in all treatments. In contrast, members of the class Actinobacteria did not respond to the enhanced availability of DOC by an immediate increase in growth rate, and their relative abundances declined during the incubations. In lake water members of the beta II clade seasonally constituted up to 50% of all microbes in the water column. Bacteria from this lineage annually formed a significantly higher fraction of the microbial community in the lake compartment with a higher allochthonous influx than in the other compartment. Actinobacteria represented a second numerically important bacterioplankton group, but without clear differences between the compartments. We suggest that the pelagic microbial community of the studied system harbors two major components with fundamentally different growth strategies.

Betaproteobacteria↗
PubMed2001

Microbial and quality attributes of ground pork prepared from commercial pork trim treated with combination intervention processes.

The effects of combination intervention treatments of commercial pork trim on microbial and quality attributes of the subsequent ground pork were examined. Fresh commercial pork trim was inoculated with swine feces and subjected to five different intervention treatments: (i) control (untreated), (ii) water (15 degrees C, 120 s), (iii) water followed by 2% lactic acid wash (15 degrees C, 75 s), (iv) Combination 1 (water plus lactic acid plus hot air [510 degrees C, 90 s]), and (v) Combination 2 (hot air plus water plus hot air). Following treatment, the pork trim was stored at 4 degrees C for 24 h, then ground, stuffed, vacuum packaged, and stored at 4 degrees C for 21 days. Populations of aerobic bacteria, coliforms, Escherichia coli, and lactic acid bacteria in the ground pork were monitored before treatment, after treatment (day 0), and at 2, 7, 14 and 21 days. In addition, uninoculated pork trim was treated as described above, and the color and emulsion stability of the ground product was evaluated. Ground pork prepared from trim treated with any of the treatment processes had lower initial microbial populations compared to the untreated samples. The applications of water plus lactic acid or Combination 1, which included a lactic acid wash, were more effective than water or Combination 2 at both reducing initial populations and suppressing the growth of aerobic bacteria, coliforms, and E. coli in ground pork during refrigerated storage. By day 21, populations of aerobic bacteria in ground pork prepared from control, water-treated, and Combination 2-treated trim were 8.22 to 8.32 log CFU/g, but in water plus lactic acid and Combination 1 ground pork, populations were 6.32 and 4.90 log CFU/g, respectively. Among the trim interventions examined, Combination 1 was most detrimental to the color and emulsion stability of the ground pork. The water plus lactic acid treatment provided the greatest microbial reduction and inhibition without large negative effects on quality attributes of the ground pork.

Animals↗
PubMed2002

Effect of nitrogen gas packaging on the quality and microbial growth of fresh-cut vegetables under low temperatures.

Nitrogen (N2) gas packaging for fresh-cut vegetables (lettuce and cabbage) has been examined as a means of modified atmosphere packaging (MAP) for extending the shelf life of cut vegetables. Gas composition in enclosed packages that contained cut vegetables and were filled with 100% N2 had an oxygen (O2) concentration of 1.2 to 5.0% and a carbon dioxide (CO2) concentration of 0.5 to 3.5% after 5 days of storage. An atmosphere of low concentrations of O2 and high CO2 conditions occurred naturally in the package filled with N2 gas. Degradation of cut vegetables in terms of appearance was delayed by N2 gas packaging. Because of this effect, the appearance of fresh-cut vegetables packaged with N2 gas remained acceptable at temperatures below 5 degrees C after 5 days. Treatment with acidic electrolyzed water (AcEW) contributed to the acceptability of the vegetables' appearance at 5 and 10 degrees C in the air-packaging system. N2 gas packaging did not significantly affect the growth of microbial populations (total aerobic bacteria, coliform bacteria, Bacillus cereus, and psychrotrophic bacteria) in or on cut vegetables at 1, 5, and 10 degrees C for 5 days. Microbial growth in or on the cut vegetables was inhibited at 1 degrees C for 5 days regardless of atmospheric conditions.

Bacteria↗
PubMed2001

Evidence for the microbicidal activity of a chlorine dioxide-containing oral rinse formulation in vivo.

The ability of an oral rinse preparation, containing an admixture of the oxohalogen oxidants chlorite anion and chlorine dioxide, to diminish salivary levels of Streptococcus mutans, lactobacilli and Candida albicans was investigated in a group of 33 dental patients. Patients underwent oral rinsing episodes with the above product (20 ml for a period of 60 seconds, three times daily) for a total of 14 days, and subsequently repeated this exercise with mineral water in place of the oral rinse formulation. A group of 10 dental student volunteers, conducting the same oral rinsing regimens with mineral water in place of the oral health care product, served as a control group. Salivary microorganism levels were determined both prior and subsequent to the above trial period. The results demonstrated that biocidal oxohalogen oxidants present in the oral rinse formulation tested gave rise to a substantial reduction in salivary S. mutans and lactobacilli levels (p < 0.001 and 0.005, respectively), although the decrease observed in C. albicans failed to reach statistical significance. As expected, mineral water employed as an oral rinsing system by the same group of patients, or the student control group, exerted no influence on the salivary levels of each of these microorganisms. The therapeutic, microbial and biochemical ramifications of the results obtained are discussed.

Adult↗
PubMed1998

Role of organic acids during processing to improve quality of channel catfish fillets.

A microbial preparation derived from aquacultured channel catfish fillets (Ictalurus punctatus) was acidified with 0, 1, 2 and 4% (vol/vol) weak organic and held in an ice bath at 0 degree C to simulate the chilling process. Additionally, catfish fillets were sprayed under varying pressures at 15 degrees C with organic acids to evaluate the efficacy of concentrations of organic acids and spray pressures to ameliorate the microbiological quality. To determine plate counts, the dilution fluid was neutralized to pH 7.2 with 1.0 M NaOH. The aerobic plates counts of microorganisms in the chilling water were monitored over a 20-min interval. Aerobic plate counts were found on the channel catfish fillets before and after spray washing with organic acids. Plates were incubated at 35 degrees C for 48 h. The addition of organic acids tot he microbial preparation used in simulating the chilling process significantly (P < 0.05) reduced the number of bacterial surviving. The number of surviving bacteria in the chilled water decreased with increasing concentration and time of exposure to organic acids. Propionic acid had the most detrimental effect on organisms present in the microfloral preparation followed by acetic and lactic acids. Spray washing of catfish fillets with water did not significantly (P < 0.05) affect the microbial quality of fillets. However, catfish fillets sprayed with organic (lactic and propionic) acids significantly (P < 0.05) reduced the microbial counts by 10-fold. Lactic and propionic acids were not significantly (P > 0.05) different in influencing the aerobic counts of the catfish fillets.

Animals↗
PubMed1998

Modulation of bacterial adhesion to hydrogel contact lenses by albumin.

PURPOSE: The purpose of this investigation was to measure the abilities of Pseudomonas aeruginosa and Staphylococcus epidermidis strains to adhere to two hydrogel lens materials and measure the effect of a protein-coated surface on the number of adhered bacteria. METHODS: Proteins absorbed to contact lenses during sleep were extracted, subjected to sodium dodecylsulphate polyacrylamide gel electrophoresis (SDS-PAGE), and probed for the presence of albumin. Bacterial adhesion was measured by counting bacteria adherent to contact lenses coated in vitro in increasing concentrations of albumin, examining the ability of albumin in solution to prevent adhesion to albumin-coated lenses, and examining the topography of bacterial adhesion by electron microscopy. RESULTS: Albumin adsorbed to lenses during overnight wear. In vitro studies demonstrated that Polymacon lenses adsorbed more albumin than Etafilcon A lenses. In general, the numbers of adherent bacteria increased with increasing concentration of albumin. Bacteria adhered in higher numbers to Polymacon lenses than Etafilcon A (p < 0.05). P. aeruginosa showed an increased adhesion as the amount of albumin on Etafilcon A lenses increased. There was a decrease in numbers of bacteria adhering per milligram of albumin as the level of albumin increased on Polymacon lenses. Cells tended to adhere to "deposits" on albumin-coated lenses. DISCUSSION: Albumin adsorbed onto the surface of contact lenses modulated the ability of P. aeruginosa and S. epidermidis to adhere. P. aeruginosa is commonly associated with contact lens-associated microbial keratitis, where bacterial adhesion to contact lenses is believed to be an important first step in the pathogenesis of the disease.

Adsorption↗
PubMed2005

Isolation and characterization of Shiga toxin-producing Escherichia coli from precooked sausages (morcillas).

The aim of the study was to establish the microbiological quality of morcillas, typical Argentine sausages, and to investigate the presence of Shiga toxin-producing Escherichia coli (STEC). Between October 2001 and October 2002, a total of 100 morcilla samples were analysed. Several samples showed high levels of total aerobic mesophilic bacteria counts, molds and yeasts. The samples analysed contained Enterobacteriaceae (100%) and fecal coliforms (81%), indicating inadequate application of the thermal treatment and deficient hygiene conditions during the elaboration of the product. STEC strains were isolated from three out of 100 (3%) morcilla samples. Two strains (2%) were characterized as E. coli O157:H7 stx2+stx2vh-a/eae/EHEC-hlyA and one strain (1%), as E. coli O26:H11 stx1/eae/EHEC-hlyA. Considering both the high microbial count in all tested samples and the presence of STEC strains in three of them, morcillas should be considered a food unsafe to consume when inadequately cooked.

Animals↗
PubMed2005

Intestinal microbiota and immunoglobulin E responses in 5-year-old Estonian children.

BACKGROUND: Over the last few decades, several studies from different parts of the world have indicated an increasing prevalence of allergic diseases. This has been related to environmental factors, like changes of microbial pressure. Our previous studies have demonstrated differences in the intestinal microbiota between allergic and non-allergic children. AIM: To test the hypothesis that the intestinal microbiota and IgE response are related, both in allergic and non-allergic 5-year-old Estonian children. METHODS: The study group comprised 19 allergic and 19 non-allergic 5-year-old children, selected from a larger group who had been followed from birth. The diagnosis of allergy was based on clinical examination of the children and on data obtained from the questionnaires. The faecal microbiota were quantified by seeding serial dilutions on nine different media for incubation in different environment. The composition of the gut microbiota was expressed both as absolute counts of the various species and their relative share among the total counts of identified microbiota. RESULTS: Bifidobacteria were less commonly detected in children with allergic diseases than in healthy children and clostridia comprised a higher proportion among their gut microbes. Children with specific IgE antibodies to defined allergens had higher counts of clostridia and the counts of clostridia correlated with the level of serum IgE, but only so in allergic children. In non-allergic children, the serum IgE levels showed a positive correlation with the counts of bacteroides. CONCLUSION: The development of allergic diseases seems to be associated with the composition of the gut microbial ecosystem. High counts of potential pathogens, such as clostridia, are associated with clinical manifestations of allergy and IgE antibody formation.

Bacteroides↗
PubMed2000

Storage of breast milk: effect of temperature and storage duration on microbial growth.

OBJECTIVE: To study the effect of storage duration at varying temperature ranges, the pattern of microbial isolates and the quantity of colony-forming units (CFU) on expressed breast milk. DESIGN: Cross sectional study. SETTING: Bacteriology laboratory, University of Zimbabwe in Parirenyatwa Hospital, Harare. MAIN OUTCOME MEASURES: The temperature, storage duration and types of micro-organisms in freshly expressed breast milk. RESULTS: Freshly expressed human breast milk contained microbial non-pathogens of skin flora. There was no growth of organisms in stored breast milk after four hours, eight hours, 24 hours and 72 hours storage duration at temperature ranges 0 to 4 degrees C (freezing temperature), 4 to 10 degrees C (refrigerator temperature), 15 to 27 degrees C (room temperature) and 30 to 38 degrees C (high temperature) respectively. Growth was detected after the storage durations and organisms isolated were both pathogens and non-pathogens with low counts. Average colony counts was (CFU < 200). CONCLUSION: The study revealed that storage duration for expressed breast milk should not exceed 24 hours in refrigerator temperature (4 to 10 degrees C), eight hours at room temperature (15 to 27 degrees C) and four hours at high temperature (30 to 38 degrees C). Although freezing temperature (0 to 4 degrees C) seemed safest for breast milk storage, short-term storage in a freezer is not recommended due to likely the hazards of the thawing process.

Adult↗
PubMed2006

Interindividual differences in microbial counts and biochemical-associated variables in the feces of healthy Spanish adults.

The aim of this study was to examine, over a period of 1 year, interindividual variations in the most prominent and representative of the cultivatable microbial populations in the feces of eight healthy Spanish persons. A number of biochemical variables (enzyme activities and ammonium and short-chain fatty acid [SCFA] concentrations) thought to be influenced by the GIT microbiota were also analyzed. Total cultivatable microbial counts ranged from 10(10) to 10(11) cfu/g of feces. The largest populations were obligate anaerobes belonging to the Clostridium clusters, followed by species of bifidobacteria and bacteroides. Coliforms and lactobacilli were found at a more intermediate level (10(5)-10(9) cfu/g). The predominant anaerobe populations remained quite constant over time, but all other microbial groups showed significant interindividual differences. Enzyme profiles were individual-dependent, but within subjects, moderate to high intersample variations over time were recorded for some activities. Fecal ammonium concentration was the most unpredictable variable; this fluctuated widely between individuals and samples. Acetic acid was the most abundant SCFA in the feces, followed by butyric and propionic acids. SCFA concentrations also varied according to the individual; some subjects showed specific profiles in terms of SCFA composition or concentration. The fecal microbial and biochemical parameters studied seemed to be individual-dependent. Most variables were rather stable over time, while others (e.g., ammonium concentration) varied widely.

Adult↗
PubMed2004

Bacterial density and community structure associated with aggregate size fractions of soil-feeding termite mounds.

The building and foraging activities of termites are known to modify soil characteristics such as the heterogeneity. In tropical savannas the impact of the activity of soil-feeding termites ( Cubitermes niokoloensis) has been shown to affect the properties of the soil at the aggregate level by creating new soil microenvironments (aggregate size fractions) [13]. These changes were investigated in greater depth by looking at the microbial density (AODC) and the genetic structure (automated rRNA intergenic spacer analysis: ARISA) of the communities in the different aggregate size fractions (i.e., coarse sand, fine sand, coarse silt, fine silt, and dispersible clays) separated from compartments (internal and external wall) of three Cubitermes niokoloensis mounds. The bacterial density of the mounds was significantly higher (1.5 to 3 times) than that of the surrounding soil. Within the aggregate size fractions, the termite building activity resulted in a significant increase in bacterial density within the coarser fractions (>20 mum). Multivariate analysis of the ARISA profiles revealed that the bacterial genetic structures of unfractionated soil and soil aggregate size fractions of the three mounds was noticeably different from the savanna soil used as a reference. Moreover, the microbial community associated with the different microenvironments in the three termite mounds revealed three distinct clusters formed by the aggregate size fractions of each mound. Except for the 2-20 mum fraction, these results suggest that the mound microbial genetic structure is more dependent upon microbial pool affiliation (the termite mound) than on the soil location (aggregate size fraction). The causes of the specificity of the microbial community structure of termite mound aggregate size fractions are discussed.

Acridine Orange↗
PubMed1992

A novel electrical method for the prevention of microbial colonization of intravascular cannulae.

An electrical device designed to prevent microbial attachment to plastic intravascular cannulae is described. The device produced an electrical current (10 microA) in both carbon-impregnated and 'Hydrocath' cannulae. In-vitro models were utilized to demonstrate that the current can block several mechanisms by which microorganisms gain initial access to intravascular devices, including extra- and intra-luminal routes. The electrical system prevented organisms from traversing along both the external and internal surfaces of the cannulae. Effective prevention of cannula colonization was demonstrated subsequent to challenge with Staphylococcus epidermidis, Staphylococcus aureus, Enterococcus faecalis, Proteus mirabilis, Pseudomonas aeruginosa and Candida albicans. The findings suggest that the electrical device may offer in-vivo cannula protection from microbial attachment and colonization, thereby reducing the potential for infection.

Bacterial Adhesion↗