Anaerobic Plate Research Articles

Incidence of Culture Positive Propionibacterium acnes in Shoulder Arthroscopy

Objectives:Accurate detection and diagnosis of Propionibacterium acnes infection after shoulder surgery is often challenging. Aspiration and tissue cultures yield both false negative and false positive cultures and determination of infection is not always straightforward. The purpose of our study was to measure P. acnes positive cultures from patients undergoing arthroscopic surgery, with no previous surgical history on that shoulder. Our hypothesis was that P. acnes would not be found in patients who had not previously had shoulder surgery.Methods:Seven samples were collected from 57 consecutive patients undergoing shoulder arthroscopy, without any previous shoulder surgery. An air swab was taken as a control for this study. Two skin swabs (one after skin preparation and one prior to skin closure), aspiration of joint fluid, and three samples of debrided tissue were obtained for culture. All samples were placed on three different aerobic plates and held for 48 hours. Samples were also plated on anaerobic plates and placed into a Thioglycollate broth and held for 28 days. All bacteria cultures were identified. Isolated P. acnes were tested for biotype with a Microscan Rapid Anaerobic ID and then streaked on brucella agar/ ANA CDC agar to measure hemolysis. The biotype isolated was also tested with Epsilometer tests.Results:Fifty-seven patients underwent arthroscopic shoulder surgery for subacromial decompression (22.8%), rotator cuff repair (57.9%), labrum or instability repair (19.3%). The mean age of the patients was 51 years (range 17-81). A total of 81 samples (21.8%) were positive for P. acnes in the timeframe of zero to fourteen days (Table 1). All positive cultures were non-hemolytic. Diagnosis, history of corticosteroid injection, or antibiotic received had no significant bearing on culture results. Positive skin cultures for P. acnes increased from 10.5 % before incision to 31.9 % at closure. This was even more pronounced in males as skin cultures increased from 31.3% before incision to 62.96% at closure. Fifteen (26.3%) patients had more than three cultures positive. None of the patients in this study have had signs or symptoms to suggest clinical infection of P. acnes.Conclusion:There was high rate (21.8 %) of positive culture for P. acnes culture positives in a group of patients that we would not expect to find bacteria. When samples are held for 28 days, this percent increased to 25.3%. This either represents false positives via contamination, inadequate skin preparation or may represent colonization as no patients have clinical symptoms of infection. These findings make the interpretation of positive P. acnes culture even more challenging when managing a patient with shoulder pain after surgery. The consequence of treating a false positive is not benign. There was also a remarkable increase in positive rate from culture obtained from the skin at the beginning of surgery (10.5%) as compared to at the end (31.9%). Future studies should examine alternate surgical skin preparation.

Effects of Gas Composition in the Modified Atmosphere Packaging on the Shelf-life of Longissimus dorsi of Korean Native Black Pigs-Duroc Crossbred during Refrigerated Storage.

This study was conducted to observe the effects of gas composition in modified atmosphere packaging (MAP) on the shelf-life of Longissimus dorsi of Korean Native Black Pigs-Duroc Crossbred (KNP×D) during refrigerated storage. Muscle sample was obtained from the left side of carcass of seven months old of KNP×D barrow. The sample was sliced into 1 cm in thickness, placed on trays (two slices/tray) and filled with different gas composition, i.e. 0:20:80/O2:CO2:N2 (MAP1), 30:20:50/O2:CO2:N2 (MAP2) and 70:20:10/O2:CO2:N2 (MAP3). Other slices of sample were vacuum packed (VP) as a control. All packs were stored at 5±1°C. At 12 d of storage, pH value of MAP2 and MAP3 were higher (p<0.05) than that of MAP1 and pH value of MAP1 was higher (p<0.05) than that of VP. At 6 d of storage, redness (a*) value of MAP2 and MAP3 were higher (p<0.05) than that of VP and MAP1 and, at 9 and 12 d of storage, redness value of MAP3 was higher (p<0.05) than that of VP, MAP1, and MAP2. At 3, 6, 9, and 12 d of storage, the 2-thiobarbituric acid reactive substances (TBARS) value of MAP3 was higher than that of MAP2 and TBARS value of MAP2 was higher than that of VP and MAP1. At 3, 6, 9, and 12 d of storage, volatile basic nitrogen values of MAP2 and MAP3 were higher (p<0.05) than those of VP and MAP1. At 3 d of storage, total aerobic plate counts of MAP2 and MAP3 were higher (p<0.05) than those of VP and MAP1 and, at 6 d of storage, total aerobic plate counts of MAP3 was higher (p<0.05) than that of MAP1 and MAP2. However, there was no significant different total aerobic plate count among MAP1, MAP2, and MAP3 at 9 and 12 d of storage. There was no significant different total anaerobic plate count among MAP1, MAP2, and MAP3 during storage. It is concluded that the MAP containing 30:20:50/O2:CO2:N2 gas composition (MAP2) might be ideal for better meat quality for KNP×D meat.

218 Dramatic Improvement in Endoscope Cleanliness Using a Commercial Bioburden Detection System and Implementation of a Modified Cleaning Algorithm

and 2 upper endoscopes on days 0, 7, 14 and 21 following standard protocol for mechanical cleaning and high level disinfection using an automated endoscope reprocessor. Endoscopes were stored hanging per institutional practice. A 1mL aliquot of each sample was inoculated onto trypticase soy agar with 5% sheep blood (blood agar), thiogycollate broth, a CDC anaerobic blood agar plate, and Sabouraud dextrose agar (for yeast and molds). All media were incubated at 2535C for 7 days. Organisms were identified using standard microbiological techniques; results were reported in colony forming units. Results: There were 33 positive cultures from 28 out of the 96 sites tested (29.2% overall contamination rate). 30/33 isolates were typical skin or environmental contaminants, thus clinically insignificant (Table 1). Three potential pathogens were cultured, including

Isolation, Identification and Antimicrobial Susceptibility of Anaerobic Bacteria: A Study Re-emphasizing Its Role.

Isolation, Identification and Antimicrobial Susceptibility of Anaerobic Bacteria: A Study Re-emphasizing Its Role.

Antimicrobial efficacy of two irrigation techniques in tapered and non-tapered canal preparations. A randomized controlled clinical trial.

The aim of this randomized controlled clinical trial was to investigate the antimicrobial efficacy of traditional positive pressure (PP) irrigation compared with apical negative pressure (ANP) in tapered as well as non-tapered root canal preparation techniques. Patients referred for treatment of mandibular permanent molars with necrotic pulps and apical periodontitis were considered for this study. A total of 32 eligible teeth were evaluated based on strict inclusion and exclusion criteria and randomly assigned as follows: Group 1: LightSpeed LSX 0.02 preparation and A NP irrigation (n = 8). Group 2: LightSpeed LSX 0.02 preparation and PP irrigation (n = 8). Group 3: ProTaper preparation and A NP irrigation (n = 8). Group 4: ProTaper preparation and PP irrigation (n = 8). A ll teeth were sampled immediately upon access (S1), after completion of the chemo- mechanical preparation (S2), and one week later after intracanal medication (S3). All samples were microbiologically processed immediately and plated in duplicates on aerobic plates, anaerobic plates, and chocolate plates and colonies statistically analyzed. No statistically significant differences were found between groups at S1. When comparing colony-forming unit (CFU) levels at S1 and S2 within groups, the reduction was statistically significant in all groups. While no significant difference was found in the proportion of teeth that culture positive at either S2 or S3 by shaping groups, a significant difference was noted when comparing PP irrigation and A NP groups. The percentage of samples in the PP irrigation group with a negative culture at both time points was 67%, compared to 100% among the A NP group. Within the limitations of the present study, taper and apical size failed to demonstrate a difference in microbiological reduction of cultivable bacteria. On the other hand, A NP revealed a significant difference when compared to PP irrigation.

Recycling of bowel content: The importance of the right timing

IntroductionExtracorporeal stool transport (recycling of chyme discharged from the proximal stoma end to the distal end of a high jejunostomy or ileostomy) is thought to be beneficial in preventing malabsoprtion, sodium loss, cholestasis and atrophy of the distal intestine until restoration of the intestinal continuity becomes possible. However little is known about its adverse effects. Our aim was to investigate the microbiological safety of recycling. Material and MethodNative samples were taken from the proximal stoma in 5 premature neonates who underwent an ileostomy or a jejunostomy due to necrotising enterocolitis, for qualitative culture. The first sample was drawn immediately after the change of the stoma bag, further samples were sent from the stoma bag at 30, 60, 90, 120, 150, and 180min later. The samples were inoculated by calibrated (10μl) loops onto blood agar (5% sheep blood), eosin–methylene blue agar and anaerobic blood agar, respectively (Oxoid). The aerobic plates were incubated for 18–20h at 5% CO2, whereas the anaerobic plates were incubated for 24–48h in an anaerobic chamber (Concept 400). The bacterial strains were identified to species level by specific biochemical reactions, RapID-ANA II system (Oxoid) and ID32E, Rapid ID 32 Strep ATB automatic system cards (bioMérieux). ResultsThe number of colony forming unit (CFU) of Gram-negative bacteria (mainly E. coli) exponentially increased after 30min and reached 105/ml after 120min. Gram-positive strains (primarily E. faecalis) were detected after 60min and CFU increased to 105/ml after 120min. The number of anaerobic (principally Bacteroides fragilis) CFU started to increase after 120min. In two cases coagulase negative Staphylococcus strains were isolated the earliest in the chyme. The average of total CFU approached 105/ml after 90min and exceeded 105/ml after 120min. ConclusionThe chyme in the stoma bag is colonized by commensal facultative pathogenic enteral/colonic as well as skin flora species after 120min. Recycling of stoma bag content may be dangerous after 90min.

Prevalence of Enterotoxigenic Bacteroides fragilis Detected in Stool Samples from Pediatric Inflammatory Bowel Disease Patients

Purpose: Enterotoxigenic Bacteroides fragilis (ETBF) are anaerobic enteric bacteria known to cause an acute, inflammatory diarrhea in both children and adults via its primary virulence factor the B. fragilis toxin (BFT). In murine models, ETBF causes asymptomatic, chronic colitis in C57BL/6 mice and increases colon tumorigenesis in multiple intestinal neoplasia (Min Apc+/-) mice. Prior human studies suggest an association between ETBF infection and active inflammatory bowel disease (IBD), though these studies are small in sample size. Our study aims to characterize the prevalence of ETBF colonization among pediatric control and IBD patients using combined anaerobic culture and fecal PCR diagnostic approaches. Methods: We obtained stool samples (n=259) and correlating clinical data from 105 prospectively enrolled pediatric patients with ulcerative colitis or Crohn's disease from two academic IBD centers. A single fecal sample was similarly collected from each of 105 confirmed non-IBD patients presenting to the same pediatric GI clinics. Frozen fecal samples were anaerobically cultured on Bacteroides Bile Esculin (BBE) agar to help promote Bacteroides spp. growth. Samples that did not grow on BBE or that grew poorly were plated on less selective Brucella anaerobic blood plates and/or LKV (Brucella Laked Blood Agar with Kanamycin and Vancomycin) plates in attempt to coax growth of Bacteroides spp. that may have been “stunned” by storage conditions. Any growth on Brucella blood agar or LKV plates was then transferred onto BBE. For all samples that grew on BBE, 16 single colonies were isolated and tested by touchdown PCR for the bft gene. Results: To date, 22 IBD samples have been tested. 17 grew on BBE, of which 10 samples contained isolates positive for bft by touchdown PCR (range of positive isolates per sample 1-8, average number of positive isolates per sample 3.6). In comparison, of the 14 control samples that were tested, 12 grew on BBE and 3 of these contained bft+ isolates (range 1-6, average 2.67). Conclusion: Our current data suggests that fecal carriage of ETBF is approximately twice as common in IBD patients compared to controls (45% vs. 21%, p=0.175). Analysis of our fecal bank is ongoing; updated microbiology results will be presented. We further plan to analyze the associated clinical data to determine if ETBF carriage correlates with clinical manifestations of IBD, such as disease location, severity, or timing of flares.

Association of Asinine Herpesvirus‐5 with Pyogranulomatous Pneumonia in a Mare

Association of Asinine Herpesvirus‐5 with Pyogranulomatous Pneumonia in a Mare

Comparison of antimicrobial effect of sodium hypochlorite (5.25%) and Iranian propolis on bacteria isolated from necrotizing single canal tooth with chronic apical periodontitis

The main goal of endodontic therapy is to reverse the process of periapical periodontics by removing such microorganisms from the root canal. Sodium hypochlorite (NaOCl) as common endodontic irrigant, possess problems of toxicity, odor and discoloration of operatory items. An equally effective, but safe irrigant is desirable. The purpose of this study was to compare the anti-microbial activity of propolis with that of NaOCl (5.25%) in microbial flora of necrosed teeth with apical chronic periodontitis. Seventeen necrosed single canal teeth with apical chronic periodontitis were selected. After cavity preparation, two samples were taken of each canal with sterile paper points and were immediately transferred to the laboratory in BHI and thioglycollate broth intermediately. Then, serial dilution were made and inoculated on to aerobic and anaerobic plates in the presence or absence of NaOCl (5.25%) and propolis. After incubation, the colonies were counted and reported as CFU/ml. According to the results, the mean percentages of bacterial growth inhibition in the presence of NaOCl (5.25%) in aerobic and anaerobic conditions were 39.4 and 40.86%, respectively, while in the presence of propolis they were 29.42 and 46.4%, respectively. It is revealed that in anaerobic condition propolis was significantly more effective than aerobic condition. Also, in anaerobic condition, it is more effective than NaOCl, none significantly. In the case of NaOCl, it can be mentioned that, there is no significant difference in aerobic and anaerobic condition. It can be concluded that propolis and NaOCl have antimicrobial activity against aerobic and anaerobic bacteria and propolis has antimicrobial activity equal to that of NaOCl. Key words: Antimicrobial, bacteria, propolis, sodium hypochlorite (NaOCl), root canal irrigants.

Sterility of Posterior Elements of the Spine in Posterior Correction Surgery

Prospective clinical series. To investigate the sterility of the posterior elements of the spine during posterior correction surgery. Bacterial growth in the operating field is considered one of the causes of surgical-site infection. A total of 80 consecutive patients (mean age = 19.5 years) who underwent posterior correction surgery for spinal deformities were included in the study. During surgery, specimens for bacterial culture were obtained by swabs from (1) the skin after cleansing using povidone-iodine scrub solution but before draping, (2) laminae immediately after exposure, (3) laminae immediately after screw placement, (4) laminae immediately before wound closure, (5) a small piece of bone obtained from the spinous process immediately after exposure and placed on a sterile dish during surgery as a control, kept covered, and (6) a similar sample as (5), kept uncovered. The culture was conducted on both blood agar and Gifu anaerobic medium agar plates. No patient developed surgical-site infection. The culture was positive in specimen (S) 1 in 25 patients (31.3%), S2 in 20 (25%), S3 in 25 (31.3%), S4 in 26 (32.5%), S5 in 6 (7.5%), and S6 in 7 (8.8%). Bacterial species included Propionibacterium acnes in 15 specimens, Propionibacterium species in 9, and others in 10. Of the 25 patients with a positive culture in S1 and 55 patients without, 22 (88%) and 26 (47.3%), respectively, demonstrated a positive culture in specimens obtained during surgery. The culture was more frequently positive in specimens obtained immediately before wound closure than in those harvested immediately after exposure and isolated from the surgical field. The results suggest that bacterial contamination of the operating field may originate from the skin of the patient during surgery.

Quality of olive oil reformulated MRE entrée packaged in oxygen-absorbing film

An iron-based oxygen absorber (ABSO2RB®) activated by moisture was incorporated into a retort laminate and used to package chicken pesto with noodles. The effect of packaging material (regular MRE and oxygen-absorbing pouches) and reformulation with olive oil on the quality and shelf life of the entrée were investigated. Physical properties (color, texture, moisture, water activity), chemical properties (pH, TBARS), and microbiological quality (Total aerobic, coliforms, Escherichia coli, Yeast and Molds, Anaerobic plate counts) were measured in triplicates in an accelerated shelf-life study for 6 months at 37.8 °C. Samples stored at 26.7 °C for 12 months served as calibrated controls. Consumer and trained panel tests were carried out using a 9-point hedonic scale. The ABSO2RB® pouches performed well in terms of seal integrity and strength and limited the formation of rancid fatty acids in olive oil throughout the shelf-life study. Soybean formulations in ABSO2RB® pouches had the lowest (p < 0.05) Thiobarbituric Acid Reactive Substances (TBARS) value. Consumer and trained panelists accepted the olive oil formulations, in both packages. Results from this study will help MRE developers to expand the number of items using healthier oils. If future considerations to replace MRE packaging are needed, the ABSO2RB® film will be a suitable alternative.

Safety and intestinal microbiota modulation by the exopolysaccharide-producing strains Bifidobacterium animalis IPLA R1 and Bifidobacterium longum IPLA E44 orally administered to Wistar rats

Bifidobacterium animalis subsp. lactis IPLA R1 and Bifidobacterium longum IPLA E44 strains were tested for their safety and ability to modulate the intestinal microbiota in vivo. Chemically simulated gastrointestinal digestion showed considerably lower survival of E44 than R1 strain, the first microorganism also being more sensitive to refrigerated storage in 10% skimmed milk at 4°C. Harmful glycosidic activities were absent, or at low levels, in the strains R1 and E44. Both strains were sensitive to most antibiotics and resistant to aminoglycosides, a common feature in bifidobacteria. Similar to several other bifidobacteria strains, B. animalis subsp. lactis IPLA R1 displayed a moderate resistance against tetracycline which correlated with the presence of tet(W) gene in its genome. The general parameters indicating well-being status, as well as translocation to different organs and histological examination of the gut tissues, revealed no changes induced by the administration of bifidobacteria to rats. Twelve-week-old male Wistar rats were distributed into three groups, eight rats in each. Two groups were administered daily over 108cfu of the corresponding strain suspended in 10% skimmed milk for 24days, whereas rats in the placebo group received skimmed milk without microorganisms added. The microbiota and short chain fatty acids (SCFA) were monitored in faeces at different time points during treatment and in caecum content at the end of the assay. Quantitative PCR (qPCR) showed that faecal and caecal Bifidobacterium levels were higher in bifidobacteria-fed rats than in the placebo rats at the end of the intervention, whereas total anaerobic plate counts did not show significant differences. Quantification of B. animalis and B. longum by qPCR showed that, independent of the microorganism administered, treatment with bifidobacteria resulted in higher levels of B. animalis in the caecum. PCR-DGGE analysis of microbial populations revealed a higher diversity of bands in caecum content of rats fed B. animalis IPLA R1 than in the placebo group and rats fed B. longum IPLA E44. Remarkably, although no variations in the proportion of acetate, propionate and butyrate were found, at the end of the assay the total SCFA concentration in the faeces of rats fed bifidobacteria was significantly higher and those in caecum content significantly lower, than that of the placebo group. This suggests a displacement of the SCFA production to parts of the colon beyond the caecum in rats receiving bifidobacteria. Therefore, the oral administration of B. animalis IPLA R1 and B. longum E44 can be considered safe, these microorganisms having the ability to modulate the intestinal microbiota of rats by influencing SCFA and the bifidobacterial population levels.

A method for assaying perchlorate concentration in microbial cultures using the fluorescent dye resazurin

Low concentrations (μg/L) of the perchlorate anion, ClO 4 −, have been measured in surface and ground water supplies in many locations throughout the United States. Perchlorate is known to affect the function of the thyroid gland in mammals and its toxicity primarily results from its inhibition of thyroid hormone output. The major sources of perchlorate contamination in surface and ground waters are defense contractors, military installations, propellant manufacturers and agriculture. The currently accepted method of perchlorate analysis, recommended by the US EPA, is neither fast nor easy to use and requires purchase of an expensive high performance ion chromatograph (IC). The novel method described here uses dye resazurin to measure perchlorate reduction by bacterial cultures and bacterial consortia in a high-throughput, multi-well, culture plate format. The method is based on the observation that perchlorate reduction and the decrease of resazurin fluorescence occur simultaneously in perchlorate degrading cultures. The bioassays were performed in anaerobic serum bottles or 96-well plates with constant shaking, using a minimal ATCC medium with 10 mM acetate as electron donor/carbon source and 200 ppm perchlorate as an electron acceptor. Fluorescence measurements with excitation at 570 nm and emission at 590 nm were taken in 20 min intervals. Changes in perchlorate concentration were confirmed using IC. Based on the experimental data, a simple model showing the correlation between perchlorate concentration in microbial culture and resazurin fluorescence level was proposed. Other dyes including redox indicators, reactive azo dyes and electron shuttle chemicals were also tested for comparison and were found less useful.

Bacterial and fungal organisms in otitis externa patients without fungal infection risk factors in Erzurum, Turkey

SummaryAim: To describe the bacterial and fungal organisms in otitis externa patients without other risk factors for fungal infections.Study designCross sectional cohort descriptive study.Materials and MethodsEar swabs were obtained from 362 patients aged 1 to 55 years old with clinically diagnosed otitis externa in Erzurum, Turkey, between January 2006 and April 2007, and cultured for aerobic and anaerobic bacteria and fungi, using EMB, 5% sheep's blood, chocolate agar, anaerobic blood agar plate, thioglycollate broth and sabaroud agar using standard microbiological technique to diagnose isolates.Results219 cultures were positive and a total of 267 isolates were obtained. Of the isolates, 68.16% (n: 182) were aerobic or facultative bacteria, 1.12 % (3) were anaerobic bacteria, 30.71 % (82) were fungi and 17.5 % (38) were polymicrobial infections.ConclusionFungal organisms especially Candida species may be isolated from ears of otitis externa patients without fungal infection risk factors such as ear self-cleaning, local antimicrobial, antifungal or corticosteroid drops or systemic antimicrobial or antifungal agents within the preceding week. Bacterial and fungal cultures may be recommended, and anti-fungal agents may be added, to treatment regimens in patients with otitis externa.

Evaluation of 0.1% Ammonium Hydroxide to Replace Sodium Tripolyphosphate in Fresh Meat Injection Brines

Paired USDA Select beef strip loins (n = 10), aged 2 d, were injected with either an alkaline-based (3.6% sodium chloride, 1% Herbalox seasoning, adjusted to pH 10 with ammonium hydroxide [approximately 0.1%, FFC grade]) or a phosphate-based (3.6% sodium chloride, 1% Herbalox seasoning, 4.5% sodium tripolyphosphate) brine. Steaks were evaluated for 19 d. Overall, phosphate-injected steaks performed better than alkaline-injected steaks with respect to cook yield, water holding capacity, lipid oxidation, color stability, tenderness, and juiciness. Phosphate-injected steaks also had less purge than alkaline-injected steaks, as confirmed by composition analysis. Phosphate-injected steaks were higher in moisture and ash content, and were nearly 2% lower in protein content. Alkaline-injected steaks had significantly lower aerobic (approximately 1 log lower) and anaerobic (approximately 2 log lower) plate counts. Final meat pH probably contributed to the differences observed between treatments. The final pH of phosphate-injected steak was 5.99 while that of alkaline-injected steak was 5.73. Further research should be conducted to determine the concentration of ammonium hydroxide needed in the alkaline-based brine to increase the final meat pH to similar levels found in the phosphate-injected steaks.

Automated Yeast Mating Protocol Using Open Reading Frames from Saccharomyces cerevisiae Genome to Improve Yeast Strains for Cellulosic Ethanol Production

Engineering the industrial ethanologen Saccharomyces cerevisiae to use pentose sugars from lignocellulosic biomass is critical for commercializing cellulosic fuel ethanol production. Approaches to engineer pentose-fermenting yeasts have required expression of additional genes. We implemented a high-throughput strategy to improve anaerobic growth on xylose and rate of ethanol production by evaluating overexpression of each native S. cerevisiae gene from a collection of haploid PJ69–4 MATa strains expressing the gene open reading frames (ORFs) mated to a haploid PJ69–4 MATalpha strain expressing the Piromyces sp.E2 xylose isomerase (XI) gene. The resulting 6113 diploid strains containing the XI gene and a different yeast gene ORF were screened for growth on xylose in anaerobic plate cultures using an integrated robotic workcell. Nine unique strains were isolated; two were found to no longer grow on glucose; seven were further evaluated for fermentation of alkaline peroxide pretreated enzymatically saccharified wheat straw hydrolysate. All successfully used glucose and xylose, consuming most of the glucose and a small amount of the xylose. Transforming the strains with an additional vector expressing xylulokinase gene did not improve anaerobic growth on xylose but improved glucose use and ethanol production on the hydrolysate, with three strains giving maximum ethanol production ≥ 14.0 g L −1 .

EFFECT OF FLAXSEED FLOUR AND PACKAGING ON SHELF LIFE OF REFRIGERATED PASTA

ABSTRACT The effects of flaxseed (Linum usitatissimum) flour (FF) and packaging conditions on microbial counts, lipid stability and cooking quality were determined for fresh pasta stored 7 weeks at 4C. Fresh pastas made from semolina or semolina blended with 15% (w/w) FF (FF-pasta) were packaged in metallized bags under three conditions: ambient air, nitrogen and vacuum. Packaging conditions did not affect aerobic or anaerobic plate counts. Mold and yeast counts were lower for pasta packaged under vacuum than under ambient air or nitrogen. Compared with traditional fresh pasta, FF-pasta had lower microbial counts during storage. Free fatty acid content in FF-pasta increased from 1.9 to 2.4% during storage. Lipid oxidation was lowest with vacuum-packaged pasta. Packaging conditions had little or no effect on cooking quality. Compared with traditional pasta, FF-pasta had lower cooked firmness and cooking loss. Cooked firmness was found to decrease only during the first week of storage; no further decrease occurred during the subsequent weeks. PRACTICAL APPLICATIONS This research would have practical applications to the fresh, refrigerated pasta industry. Although limited in scope, the results indicate that flaxseed flour (FF) has some bacteriostatic and fungistatic activity that may be useful in extending shelf life of fresh, refrigerated pasta/noodle products, and that further research to improve and maintain the cooking quality of FF-pasta during storage is needed.

Evaluation of Conventional Microbiological Procedures and Molecular Genetic Techniques for Diagnosis of Infections in Patients with Implanted Orthopedic Devices

Evaluation of Conventional Microbiological Procedures and Molecular Genetic Techniques for Diagnosis of Infections in Patients with Implanted Orthopedic Devices

Incidence of spore-forming bacteria in unsweetened evaporated milk brands in Nigeria

A total of forty-five samples of three most commonly consumed unsweetened evaporated milk brands purchased from retail outlets in South-western Nigeria were examined for occurrence of spore-forming bacteria. All the samples had high numbers of spore-forming bacteria of the genera Bacillus spp and Clostridium spp. with mean total aerobic viable counts of 2.15x105cfuml-1 for br and A, 0.95x105cfuml-1 for brand B and 0.69x105cfuml-1 for brand C. Total anaerobic plate counts ranged from 0.13x105 for brand C, to 0.54x105 for brand B and 1.67x105 for brand A. The organisms isolated from the three brands were identified as Bacillus cereus, Bacillus licheniformis, Bacillus coagulans, Bacillus stearothermophilus, Bacillus subtilis and Clostridium perfringens, with B. subtilis having the highest frequency of occurrence (93.33%). Samples were subjected to four different pasteurization treatments: 550C for 30 min, 800C for 15 min, 900C for 10 min and 1200C for 30 sec, to determine a more efficient process. No growth was observed on culture plates of samples pasteurized at 1200C for 30 sec, except on aerobic plates of brand A. However the milk samples treated under this regime curdled. Samples pasteurized at 800C for 15 min recorded the least counts next to samples treated at 1200C for 30 sec, without causing the samples to curdle. Keywords: Evaporated milk, pasteurization, sporeforming bacteria, viable counts. Nigerian Food Journal Vol. 25 (1) 2007: pp. 137-144

A comparative study of high pressure sterilisation and conventional thermal sterilisation: Quality effects in green beans

Experiments were conducted to compare the colour, texture and microbiological quality of green beans that had been either high pressure sterilised (HPS) using commercially achievable pressures (a pre-heat to 86 °C followed by two treatments of 2 min at 700 MPa) or were conventionally thermally sterilised (Fo 1 to 3 min with a retort temperature of 115 °C). Samples were assessed immediately after processing and after 7 months of ambient storage. HPS treated samples were generally darker in appearance (L⁎ values shifted downwards) compared with heat treated (F0 3 min) samples. The a⁎ values for HPS samples were significantly (P 0.05). HPS treated samples were typically twice as firm as F0 3 min treated samples (P < 0.05). There was some softening over storage but this differential in firmness was maintained after 7 months. Total aerobic and anaerobic plate counts and spore counts after storage were below the limits of detection in all samples apart from one canned sample where leaker spoilage had occurred. Industrial relevance Thermal sterilisation technologies are used to produce ambient stable products but frequently these products suffer deleterious quality changes such as colour and texture modification as a result of processing. There is industrial interest in any technologies with the potential to produce ambient stable products with improved retention of ‘fresh’ characteristics. High pressure sterilisation is a promising method for the production of ambient stable products with improved quality.