Aerobic Counts Research Articles

Microbial Evaluation of Root Canals after Biomechanical Preparation with Manual K-files, Manual H-files, and Kedo-SG Blue Rotary Files: An In Vivo Study.

The purpose of the present study was to comparatively evaluate the efficacy of Kedo-SG blue rotary files, manual K-files, and manual H-files in eliminating the root canal microflora of primary molars. Forty-five primary molars requiring pulpectomy were included in the study. Based on type of instrumentation, the teeth were randomly assigned to one of the three groups: group A: Kedo-SG blue rotary files, group B: manual H-files, and group C: manual K-files. Sterile absorbent paper points were used for sample collection and stored in sterile Eppendorf tubes containing saline as transport medium. Culturing was done on thioglycolate agar and blood agar media for the cultivation of anaerobic and aerobic microbes, respectively, and recorded as colony-forming units (CFU) using digital colony counter. Wilcoxon signed-rank test and one-way analysis of variance (ANOVA) test were performed for statistical analysis. Postinstrumentation, 93-96% reduction of aerobic and anaerobic microbial count was recorded in group A. Whereas, it was 87-91% reduction in group B and 90-91% reduction in group C. No statistically significant difference was noted between the three groups. Kedo-SG blue rotary files showed a better reduction of microbes in root canals when compared to manual instrumentation. However, there was no significant difference between manual and rotary instrumentation in microbial reduction of primary root canals. Lakshmanan L, Jeevanandan G. Microbial Evaluation of Root Canals after Biomechanical Preparation with Manual K-files, Manual H-files, and Kedo-SG Blue Rotary Files: An In Vivo Study. Int J Clin Pediatr Dent 2022;15(6):687-690.

Microbiological and chemical safety ofBombyx mori farmed in north-eastern Italy as a novel food source

Sericulture in Italy has old origins, but competitiveness with the Asian markets and the widespread use of pesticides have led, in the past, to a decline ofBombyx mori (BM) farming. However, this sector is characterised by future development potential due to the use of all BM products in the food sector, which would promote a sustainable production chain. The aim of the present study was to determine the nutritional composition and the presence of chemical and microbiological hazards in BM. Based on the microbiological criteria reported by the Regulation (EU) 2017/2470 and amendments for already authorised edible insect species, the samples of chrysalides met the criteria set forEscherichia coli, Listeria monocytogenes, Salmonella spp., Bacillus cereus, Coagulase positive Staphylococci, and sulphite-reducing anaerobes. Some samples were not compliant with the criteria set for total aerobic colony count,Enterobacteriaceae, yeasts and moulds. B. cereus was detected only in cocoon samples. Traces of fungicides, polycyclic aromatic hydrocarbons, dioxins-PCBs and heavy metals (Pb and As) were observed in chrysalides, chrysalis oil and defatted chrysalis meal. Cd and Hg were not detected in any sample. Traces of mycotoxins were detected only in chrysalis oil and defatted chrysalis meal, not in chrysalides. The content of lipids and proteins in chrysalides ranged between 34.42-39.19% and 38.13-50.17%, respectively. In addition, no difference was observed in element content (P, S, Cl, K, Ca, Mn, Fe, Cu, Zn) between chrysalides and chrysalis meal. The present study highlights the possible impact of contamination of the rearing and processing environments on the microbial and chemical safety of BM and derivative products.

A promising insight into the inhibition of lipid oxidation, protein degradation and biogenic amine accumulation in postmortem fish: Functional glazing layers of modified bio-polymer

This study focused on a glazing layer made by modified bio-polymer to inhibit chemical variations in super-chilled postmortem fish. Essential oils were extracted from tangerine peel and their major antioxidant and antimicrobial components were identified. The essential oils were introduced into chitosan material as functional agents to improve the performance as freshness-keeping glazing layers for super-chilled tilapia. During the storage, antimicrobial effects of glazing significantly decreased the bacterial growth, as the growth of total bacterial count (TBC) decreased from ∼12.8 log CFU/g to ∼ 3.5 log CFU/g and that of total aerobic count (TAC) decreased from ∼11.1 log CFU/g to ∼ 3.3 log CFU/g. Antioxidant effects of glazing led to decreases of peroxide value (PV) from 6.41 meq/kg to ∼2.5 meq/kg and thiobarbituric acid reactive substances (TBARS) content from 1.09 mg MDA/kg to ∼ 0.5 mg MDA/kg at the end of the storage. Glazing inhibited the change of corruption degree reflected by K-value and protein decomposition reflected by the contents of trichloroacetic acid (TCA) soluble peptides and total volatile basic nitrogen (TVB-N). Glazing also limited the contents of main biogenic amines (histamine, putrescine, cadaverine, spermine, spermidine, tyramine, tryptamine) within relatively low levels.

Assessment of Physicochemical and Microbiological Qualities of Potable Water Sources in Okorenkoko, Delta State Nigeria

Accessibility of Potable water in rural and riverine communities have reduced drastically in recent times. A total of six borehole water samples and a freshwater sample were obtained from Okerenkoko community in Delta State, Nigeria. The water samples were analyzed for physicochemical and microbiological parameters using standard procedures. Pearson correlational analysis was employed to evaluate the level of association of the data using Statistical Package for Social Sciences version 23. Our results showed that pH concentration values ranged from 5.62 to 7.81, electrical conductivity had 10.03 to 490.01 µS/cm, dissolved oxygen varied from 3.90 to 7.91 mg/L, COD had 10.01 to 50.03 mg/L. The fecal coliform count ranged from 4- 2400 MPN/ml, while the surface water had a fecal coliform count 2400 MPN/ml; fungal count 3.1 Log10CFU/ml and 3.6 Log10CFU/ml respectively, Total aerobic count had a maximal concentration value of 5.8 Log10CFU/ml and 5.4 Log10CFU/ml; Total Salmonella Shigella Count it had a concentration of 4.0 Log10CFU/ml. Microbes associated with the water samples were Bacillus sp., Escherichia sp., Staphylococcus sp., Streptococcus sp., Shigella sp., Proteus sp., Pseudomonas sp., Klebsiella sp., Vibrio sp. and Micrococcus sp. There is an urgent need to source-track the trajectory of pollutants from both from domestic and industrial activities. There is need that the government at all levels should improve the available potable water resources in Okerenkoko community.

Investigation of Antibiotic Residue, Nitrofuran Compounds, Microbial Properties and Heavy Metal Amount in Rainbow Trout (Oncorhynchus mykiss)

ABSTRACT The aim of this study was to determine the pathogenic microorganisms, antibiotic residues, and metal concentrations in rainbow trout (Oncorhynchus mykiss) fillets grown in 3 different regions in Trabzon and to determine their compliance with the limit values determined by national (Turkish Food Codex) and international legislation (Codex Alimentarius commission, European Comission). Of the 46 antibiotic residues and 4 nitrofuran residues searched, none of the fillets were detectable and all were below the maximum residue limit. The highest number of aerobic colony count was found at 3.2 × 104 (A2 location). Enterobacteriaceae<10 cfu/g, Escherichia coli<3 MPN/g and<10 cfu/g, Staphylococcus aureus<10 cfu/g, and Coliform bacteria<3 MPN/g and<10 cfu/g were detected. Listeria monocytogenes, Salmonella spp. Vibrio cholera, and Vibrio parahaemolyticus were not found in any of the locations. Metal concentrations, Pb, Cd, and Hg observed were below the limits set by the legislation. The results show that rainbow trout fillets cultivated in offshore fish farms in 3 different regions are below the maximum limit values specified in national and international regulations in terms of antibiotic residue amount, heavy metal content, and microbiological properties.

SG-APSIC1023: Contamination of the geriatric medicine outpatient rehabilitation gym environment and the effectiveness of our current disinfection methods with patient hand hygiene practices

Objectives: To quantify the microorganism burden of rehabilitation gym equipment surfaces as well as to assess the effectiveness of patient’s practice of hand hygiene and our current disinfection methods to reduce burden and transmission of microorganisms during rehabilitation sessions. Methods: A prospective study of environmental contamination using microbiology culture in Khoo Teck Puat Hospital Geriatric Medicine Outpatient Rehabilitation Gym. Results: For both the control and intervention group, the total aerobic bacterial count on the gym equipment after patient use is significant and increase up to 360 CFU per swab. In the control and intervention groups, the total aerobic bacterial counts on the gym equipment before patients’ use were negligible (&lt;10 CFU per swab). The total aerobic bacterial count of the equipment remained negligible (&lt;10 CFU per swab) after patient use and immediate disinfection. We detected discrepancies between the results of the total aerobic bacterial count after patient use between the control and intervention groups. Conclusions: Outpatient rehabilitation gyms are potential reservoirs of microorganisms, which may further contribute to the transmission of healthcare-associated pathogens. In this study, an intervention in which cleaning equipment was wiped with alcohol wipes was effective in reducing microorganism transmission in the rehabilitation gym environment and should be considered as part of our infection control strategy. The additional step of involving our patients in using hand rub before the start of their therapy sessions can provide additional benefit in reducing microorganism transmission only if patients adhere to the World Health Organization (WHO) recommended 7 steps of proper hand rub. Good patient education on hand hygiene is equally as important as that for healthcare professionals to control environmental contamination.

Effects of UV-C Irradiation and Vacuum Sealing on the Shelf-Life of Beef, Chicken and Salmon Fillets.

One-third of the world's food supply is lost, with meat being a major contributor to this loss. Globally, around 23% of all meat and 35% of all seafood products are lost or wasted. Meats and seafood products are susceptible to microbial spoilage during processing, storage, and distribution, where microbial contamination causes significant losses throughout the supply chain. This study examined the efficacy of UV-C irradiation and vacuum-sealing in preventing microbiological deterioration in beef, chicken, and salmon fillets. The samples were sterilized using a constant UV-C irradiation dose of 360 J/m2 and stored under a reduced pressure of 40 kPa. A microbiological analysis was conducted daily to examine the microbial contamination, which included counting the colonies of Pseudomonas spp., aerobic bacteria, lactic acid bacteria (LAB), Salmonella, and Escherichia coli, as well as monitoring the increase in pH levels. The results demonstrated a statistically significant difference (p > 0.05) in the aerobic bacteria counts between the storage conditions and storage days in all samples, which is a primary indicator of microbial spoilage. In contrast, the differences varied in the Pseudomonas spp. and LAB counts between the storage conditions and storage days, and there was no significant difference (p < 0.05) in the pH levels between the storage conditions. The results indicate that the combination of UV-C irradiation and vacuum sealing effectively inhibits microbial growth and extends the shelf-life of beef, chicken, and salmon fillets by 66.6%.

SG-APSIC1154: Evaluation of disposable antimicrobial curtains in an ambulatory cancer center

Objectives: The prevention of nosocomial infection is a challenge for all healthcare institutions. Privacy curtains are often changed infrequently, and they are difficult to clean. Contaminated curtains can be touched by healthcare providers and patients, which may result in indirect transmission of infectious disease. Hence, we evaluated the impact of the antimicrobial properties of disposable curtains and their cost-effectiveness. Methods: This descriptive exploratory study was conducted in an ambulatory cancer center in 2017. Privacy curtains were assigned to 2 cohorts, labelled E1 and E2. They were placed in the clinical areas for 6–12 months. Moist swab samples for MRSA, VRE, and CP-CRE cultures were obtained from the leading edges of the curtains during the evaluation period. Also, 10-cm × 10-cm swatches were cut from the high-touch areas of curtains and were tested for total aerobic count on the first of the month and quarterly thereafter. Results: All bacterial culture swabs obtained from the E1 and E2 cohorts of curtains were negative. The total bacterial plate count results from E1 curtains were negative for up to 1 year. However, the total bacterial plate count results for E2 curtains were positive in the sixth month. Using disposable curtains yielded an annual cost saving of ~50%. Conclusions: The use of appropriate impregnated antimicrobial disposable curtains can improve patient safety in the clinical areas. These curtains may eliminate potential sources of infection and thereby decrease the rate of nosocomial infection. They also save significant institutional costs by reducing frequent laundry and manpower requirements needed for the installation of curtains.

The Influence of Biopolymer Coating Based on Pumpkin Oil Cake Activated with Mentha piperita Essential Oil on the Quality and Shelf-Life of Grape

This work aimed to determine the influence of biopolymer coatings based on pumpkin oil cake, with and without the addition of Mentha piperita essential oil, on the quality and shelf-life of the Afus Ali variety of grapes, stored at room temperature and in the refrigerator. Furthermore, a 10% (w/w) aqueous solution of composite pumpkin oil cake (PuOC) with the addition of 30% glycerol was prepared at 60 °C and pH 10. The active biopolymer coating was prepared similarly by adding 1% (v/v) Mentha piperita essential oil. The quality of packed grapes was tested by determining the dry matter content, total sugar content, total acidity, alcohol content, total phenolic compounds content, and total flavonoid content, as well as by determining the antioxidant activity, through the application of the DPPH, FRAP and ABTS tests. Additionally, microbiological parameters were investigated: total aerobic microbial count, yeasts, and molds. The obtained results proved that in all tested samples, over a certain period of time, the content of dry matter, content of phenolic and flavonoids substances and sugar content decreased as a consequence of the spoilage of grapes, that is, the consumption of sugar for the production of alcohol, which consequently leads to the total acidity increasing. The application of lower storage temperatures and active coating (with Mentha piperita essential oil) had a positive effect on all inevitable reactions. Grapes’ antioxidant potential may be enhanced or maintained by applying PuOC coating with or without Mentha piperita essential oil, which is best observed in the case of the DPPH test. The uncoated sample stored at room temperature had the largest decrease in DPPH values during storage, with changes ranging from 2.119 mg/g to 1.471 μmol mg/g. The samples, coated with PuOC and PuOC with the addition of essential oil, had uniform DPPH values throughout the entire storage period. Additionally, regarding phenolic content, at the end of storage period the highest phenolic content was observed in samples with active coating stored at room temperature (734.746 ± 2.462) and at refrigerator temperature (680.827 ± 0.448) compared with untreated samples and with samples with plain PuOC coating. The presence of active essential oil in the applied coating significantly affected the microbiological profile of grapes during the storage period. Besides the positive impact of the applied lower storage temperature, the effectiveness of the applied active packaging is even greater (microbiological results were in the order of PuOC+essential oil &lt; PuOC &lt; Control). The developed artificial neural networks were found to be adequate for modeling the microbiological profile, antioxidant activity, phenolic and flavonoid content.

Quality of Tenebrio molitor Powders: Effects of Four Processes on Microbiological Quality and Physicochemical Factors.

Tenebrio molitor, the first edible insect approved as a novel food in the EU, is a promising candidate for alternative protein sources, implementing circular and sustainable production systems. This study aims to determine the microbiological quality and physicochemical properties of mealworm powders obtained by four different processing pathways. Contents of dry matter, protein, fat, ash, water activity (aw) and a range of microbial counts were measured and analyzed by one-way ANOVA with Tukey's test. Results showed small differences in the proximate composition of the powder samples (protein 55.62-57.90% and fat 23.63-28.21% of dry matter, DM), except for the one that underwent a defatting step (protein 70.04% and fat 16.84%), p < 0.05. A level of water activity of less than 0.2 was reached for all pathways. Fresh mealworm samples had high total aerobic counts (8.4 log CFU/g) but were free of foodborne pathogens. Heat treatments applied during transformation were sufficient to kill vegetative cells (reduction of 2.8-5.1 log CFU/g) rather than bacterial endospores (reduction of 0.3-1.8 log CFU/g). Results were confirmed by predictive microbiology. This study validated the efficacy of a boiling step as critical control points (CCPs) of insect powder processing, providing primary data for the implementation of HACCP plans.

HISTAMINE LEVEL AND HISTAMINE-PRODUCING BACTERIA ISOLATED FROM SALTED AND FREEZE SARDINE FISH (Sardina spp.)

Histamine is the biogenic amine responsible for scombroid poisoning in various types of fish and fish products. The study evaluated histamine content and bacteriological quality of salted and freeze sardine samples. All fish samples were cultured on Reinforced Closterdial medium; mannitol salt (MS) agar and violet red bile glucose (VRBG) agar, the positive colonies were sub-cultured on histamine-forming bacterium agar, followed by biochemical and PCR identification. Production of histamine in the fish muscles was measured by high performance liquid chromatography. The mean histamine values were about; 8.25 mg/100g. The mean of total aerobic counts was; 4×104 ± 2.1×104 while, the total anaerobic count; 5×104 ±1.2×103 Log CFU/g. Enterobacteriacea spp. about; 5×104 ±2.5×104 Log CFU/g while, the mean value of Staphylococcus spp. about; 3×104 ±3.7×104 Log CFU/g. The mean value of histamine-forming bacterial were; 3.3×106 Log CFU/g. Molecular Identification For Enterobacteriaceae were Klebsiella pneumonia, Staphylococcus xylosus, Escherichia coli and Enterobacter cloacae. We concluded that during storage, there was a positive relationship between the histamine levels and the histamine-forming bacteria (HFB) numbers, while, histamine and the bacteria forming histamine were recorded in all examined sardine samples. Key words: histamine; Escherichia coli; Klebsiella pneumonia; molecular identification; scombroid; Staphylococcus xylosus

Nutritional properties, microbial and sensory quality, and formation of biogenic amines in wild-grown mushrooms (Cantharellus cibarius & Boletus edulis) from Austrian local markets

Wild-grown mushroom species chanterelle (Cantharellus cibarius) and porcini mushroom (Boletus edulis), available at Austrian local markets, were evaluated regarding microbial and sensory quality, content of biogenic amines, and proximate chemical composition. Chemical composition varied widely with species, but showed no correlation with sensory quality and microbial load. Chanterelles were characterized by high levels of aerobic mesophilic counts, regardless of sensory quality. In both mushroom species, poor sensory quality was associated with increased counts of Enterobacteriaceae. In porcini mushrooms, the level of ß-phenylethylamine, cadaverine, histamine, and tyramine correlated to the count and type of microorganism. The level of biogenic amines does not pose a risk to healthy individuals. Almost half of the samples purchased were sensorically deficient, indicating handling under poor hygienic conditions or being offered for sale for too long. To obtain wild mushrooms of excellent quality, all relevant stakeholders at harvest and retail level should be trained in hygienic handling of mushrooms.

Microbial Communities on Samples of Commercially Available Fresh-Consumed Leafy Vegetables and Small Berries

Microbial communities on fresh-consumed plant products are an important predictor of quality and safety for the consumer. Totally, 45 samples of berry fruits (8 blackberries, 9 blueberries, 8 strawberries, 8 raspberries, 12 currants) and 40 samples of leafy vegetables (20 lettuce, 6 cornsalad, 8 rocket, 8 spinach) were analyzed using cultivation and DNA-depended methods. Total aerobic count, coliforms, and yeasts were significantly lower in fruits while counts of filamentous fungi were similar. Pantoea, Enterobacter, and Klebsiella were the most common colonies grown on VRBL agar. Salmonella was detected in single sample of cornsalad using qPCR but no sample contained Escherichia coli harboring stx1, stx2 and intimin genes. Sequencing of V4 region of bacteria 16S rRNA and ITS2 region of fungi amplified from plant tissue-extracted DNA confirmed different composition of fruit and vegetable microbiome. Pre-enrichment of bacteria in phosphate buffered water allowed deeper analysis of Enterobacteriaceae using V4–V5 region of 16S rRNA while differences among communities were described similarly. Pantoea, Klebsiella, or Staphylococcus were more frequent in berries while Pseudomonas, Flavobacterium, or Sphingobacterium in leafy vegetables. Comparison of inner and outer leaves of head-forming lettuces (6 iceberg, 5 romain) showed that outer leaves are colonized by more bacteria with higher diversity. Microbiological safety of fresh production requires more attention as the potentially pathogenic bacteria were detected, particularly in leafy vegetables. However, the true pathogenicity of such bacteria needs further research.

Evaluation of the Efficacy of Antioxidant Extract from Lemon By-Products on Preservation of Quality Attributes of Minimally Processed Radish (Raphanus sativus L.).

The aim of this work was to enhance the use of a food-grade antioxidant extract obtained from lemon processing byproducts (peel, pulp and seeds) to extend the shelf life of minimally processed radishes. The extract (LPE) was previously characterized in terms of total phenolic (6.75 ± 0.34 mg GAE g-1 d.w.) and flavonoid content (2.04 ± 0.09 mg CE g-1 d.w.) and antioxidant activity, and eriocitrin and hesperidin were identified as the most prevalent phenolic compounds by a UHPLC system. The effects of different dipping aqueous solutions (UCR, DRa, DRb) and alginate-based edible coating formulations (CRc, CRd) with and without the antioxidant extract were studied on the quality parameters of minimally processed radishes, characterized regarding their microbiological and physicochemical characteristics for up to 14 days at 3 °C. The coating formulated with LPE delayed the radish respiration process, as well as resulting in less color variation (ΔE < 3) and reduced mesophilic aerobic count values (4.49 ± 1.43 log CFU g-1), proving the effectiveness of LPE as a value-added ingredient in developing post-harvest strategies to prolong the shelf life of minimally processed vegetables. Indeed, coated samples without the extract showed a clear development of rotting, which led to the end of their shelf life on their 7th day of storage.

Correlation Analysis of Microbial Contamination and Alkaline Phosphatase Activity in Raw Milk and Dairy Products.

Microbial contamination in raw milk and dairy products can detrimentally affect product quality and human health. In this study, the aerobic plate count, aerobic Bacillus abundance, thermophilic aerobic Bacillus abundance, and alkaline phosphatase activity were determined in 435 raw milk, 451 pasteurized milk, and 617 sterilized milk samples collected from 13 Chinese provinces (or municipalities). Approximately 9.89% and 2.22% of raw milk and pasteurized milk samples exceeded the threshold values for the aerobic plate count, respectively. The proportions of aerobic Bacillus in raw milk, pasteurized milk, and sterilized milk were 54.02%, 14.41%, and 1.30%, respectively. The proportions of thermophilic aerobic Bacillus species were 7.36% in raw milk and 4.88% in pasteurized milk samples, and no bacteria were counted in sterilized milk. Approximately 36.18% of raw milk samples contained >500,000 mU/L of alkaline phosphatase activity, while 9.71% of pasteurized milk samples contained >350 mU/L. For raw milk, there was a positive correlation between the aerobic plate count, the aerobic Bacillus abundance, and the alkaline phosphatase activity, and there was a positive correlation between the aerobic Bacillus abundance, the thermophilic aerobic Bacillus count, and the alkaline phosphatase activity. For pasteurized milk, there was a positive correlation between the aerobic plate count, the aerobic Bacillus abundance, and the thermophilic aerobic Bacillus count; however, the alkaline phosphatase activity had a negative correlation with the aerobic plate count, the aerobic Bacillus abundance, and the thermophilic aerobic Bacillus abundance. These results facilitate the awareness of public health safety issues and the involvement of dairy product regulatory agencies in China.

Influence of Bacterial Contamination and Antibiotic Sensitivity on Cryopreserved Sperm Quality of Indian Red Jungle Fowl.

Aims: Bacterial contamination may occur in feces during collection and processing of semen. Bacteria not only compete for nutrients with spermatozoa but also produce toxic metabolites and endotoxins and affect sperm quality. The aim of the present study was to investigate the effect of antibiotic supplementation on the sperm quality of Indian red jungle fowl, estimation and isolation of bacterial species and their antibiotic sensitivity. Materials and Methods: Semen was collected and initially evaluated, diluted, and divided into six experimental extenders containing gentamicin (2.5 μg/mL), kanamycin (31.2 μg/mL), neomycin (62.5 mg/mL), penicillin (200 U/mL), and streptomycin (250 μg/mL), and a control having no antibiotics were cryopreserved and semen quality was evaluated at post-dilution, post-cooling, post-equilibration, and post-thawing stages (Experiment 1). A total aerobic bacterial count was carried out after culturing bacteria (Experiment 2) and subcultured for antibiotic sensitivity (Experiment 3). Results: It was shown that penicillin-containing extender improved semen quality (sperm motility, plasma membrane integrity, viability, and acrosomal integrity) compared with the control and other extenders having antibiotics. The bacteria isolated from semen were Escherichia coli, Staphylococcus spp., and Bacillus spp. Antibiotic sensitivity results revealed that E. coli shows high sensitivity toward neomycin, kanamycin, and penicillin. Staphylococcus spp. shows high sensitivity toward streptomycin, neomycin, and penicillin. Bacillus spp. shows high sensitivity toward kanamycin and penicillin. Conclusions: It was concluded that antibiotics added to semen extender did not cause any toxicity and maintained semen quality as that of untreated control samples, and penicillin was identified as most effective antibiotic. It is recommended that penicillin can be added to the semen extender for control of bacterial contamination without affecting the semen quality of Indian red jungle fowl.

Investigation of microorganisms in cannabis after heating in a commercial vaporizer.

There are concerns about microorganisms present on cannabis materials used in clinical settings by individuals whose health status is already compromised and are likely more susceptible to opportunistic infections from microbial populations present on the materials. Most concerning is administration by inhalation where cannabis plant material is heated in a vaporizer, aerosolized, and inhaled to receive the bioactive ingredients. Heating to high temperatures is known to kill microorganisms including bacteria and fungi; however, microbial death is dependent upon exposure time and temperature. It is unknown whether the heating of cannabis at temperatures and times designated by a commercial vaporizer utilized in clinical settings will significantly decrease the microbial loads in cannabis plant material. To assess this question, bulk cannabis plant material supplied by National Institute on Drug Abuse (NIDA) was used to assess the impact of heating by a commercial vaporizer. Initial method development studies using a cannabis placebo spiked with Escherichia coli were performed to optimize culture and recovery parameters. Subsequent studies were carried out using the cannabis placebo, low delta-9 tetrahydrocannabinol (THC) potency and high THC potency cannabis materials exposed to either no heat or heating for 30 or 70 seconds at 190°C. Phosphate-buffered saline was added to the samples and the samples agitated to suspend the microorganism. Microbial growth after no heat or heating was evaluated by plating on growth media and determining the total aerobic microbial counts and total yeast and mold counts. Overall, while there were trends of reductions in microbial counts with heating, these reductions were not statistically significant, indicating that heating using standard vaporization parameters of 70 seconds at 190°C may not eliminate the existing microbial bioburden, including any opportunistic pathogens. When cultured organisms were identified by DNA sequence analyses, several fungal and bacterial taxa were detected in the different products that have been associated with opportunistic infections or allergic reactions including Enterobacteriaceae, Staphylococcus, Pseudomonas, and Aspergillus.

Effect of non-thermal ultraviolet and ultrasound technologies on disinfection of meat preparation equipment in catering industry.

In recent years, ultraviolet and ultrasound treatments are gaining attraction as promising green decontamination technologies to ensure microbial safety in food industry. Decontamination by ultraviolet light is a physical process defined by the transfer of electromagnetic energy from a light source to an organism's cellular material and depended on the emission of radiation in the ultraviolet region (100-400 nm), specifically the UV-C region (200-280 nm) which has been demonstrated to be germicidal. Ultrasound technology is defined as sound waves with high and low frequency beyond the limit of human hearing and shows a decontamination effect that occurs as a consequence of cavitation at high power (low frequency) in general. In the present study, it was aimed to determine the effectiveness of ultraviolet light (254 nm, 10 min) and high frequency ultrasound techniques (40 kHz, 10 min) in reducing total aerobic mesophilic bacteria, yeast and mold, Esherichia coli/coliform and Salmonella spp. on the equipment surfaces used in the catering facility. For this purpose, the equipment (cutting knife, meat grinder knife, knife sharpener, cut-proof glove) used in the meat preparation department of catering facility were selected for the treatments. According to the results, appreciable reductions were achieved in total aerobic mesophilic bacterial counts of the ultraviolet treated samples (maximum difference 2.61 log cfu/cm2) and the ultrasound treated samples (maximum difference 4.07 log cfu/cm2). After ultraviolet treatment, Salmonella spp. were totally inhibited on the contaminated surfaces. Furthermore, Escherichia coli/coliform was not detected in the samples after both treatments whereas it was detected before the treatments. It has been concluded that the techniques are effective in reducing microbiological load and also ultraviolet treatment is effective on pathogenic microorganisms on food contact surfaces. As a result, the ultraviolet and ultrasound techniques are effective treatments for equipment disinfection in the catering sector and can be used industrially as it gives successful results.

Assessment of Bacteria Contaminants in Different Zones and Point Sources of Sandy Beaches in Accra, Ghana.

Bacteria are ubiquitous in the marine environment. Increasing concern for human health has led to growing interest in contamination on public beaches. The presence of pathogenic microorganisms originating from anthropogenic activities such as defecation and disposal of sewage on beaches are of special concern. In this study, presence of pathogenic bacteria and bacterial load in beach zones and point sources were investigated. Sand core samples from the subtidal zone, intertidal zone, supratidal zone and point sources from 5 beaches in Accra, Ghana, were collected and analysed. Total aerobic, coliform and Escherichia (E. coli) counts were determined for each zone in the respective beaches. Bacteria isolates were presumptively identified using biochemical tests and confirmed with MALDI-TOF MS. Mean total aerobic count and total coliform counts ranged from 2.10 to 3.01 log CFU/g and 0.29 to 2.18 log CFU/g respectively while E. coli counts ranged from 0.12 to 1.71 log CFU/g for the beaches. Total aerobic count from point sources was 2.4-folds higher than the subtidal zone while total coliform counts were 5-folds higher in the point sources compared to the supratidal zone. Point sources had 10 times (P = .0016) more E. coli counts as compared to the subtidal zone. Isolates recovered (n = 35) belonged to 10 bacteria genera. These were Bacillus spp. (25.7%), Acinetobacter spp. (14.3%), Aeromonas spp. (14.3%), Klebsiella pneumoniae (14.3%), Aerococcus viridans (8.6%), Staphylococcus spp. (8.6%), Shewanella profunda (5.7%), Rheinheimera soli (2.9%), Pseudomonas aeruginosa (2.9%), and Exiguobacterium aurantiacum (2.9%). Point sources are major contributors to contamination on beaches. The presence of potentially pathogenic bacteria in beach sand could be a public health risk. Sensitization on cleanliness in the marine environment including beaches in Ghana is needed to enhance public health and safety.

Multidrug-resistant and potentially virulent Gram-negative bacilli recovered from urine of slaughtered cattle in Makurdi, Nigeria

Objective: Many reports of bacteriuria in domestic animals allude that animals may serve as hosts and means of spreading zoonotic pathogenic and multidrug-resistant bacteria via contamination of the environment with their urine. This cross-sectional study determined the bacterial load of urine from slaughtered cattle. It investigated the resistance to antimicrobials and pathogenicity potentials of the Gram-negative bacteria recovered from urine samples. Materials and Methods: Urine samples were obtained from 52 slaughtered cattle at the Wurukum Abattoir, Makurdi, Benue State, within a month. Standard microbiological procedures were used to process the samples for the isolation and identification of bacteria. Disc diffusion technique was used to determine the antibiogram of the isolates. Standard procedures also were deployed to examine the expression of virulence factors. Results: Bacteria were isolated from 20 of the 52 urine samples, with the positive samples yield¬ing total aerobic and coliform counts of 2.8 × 103 − 9.1 ×105 and 2.5 × 102 − 3.3 × 105 CFU/ml, respectively. Species of Gram-negative bacilli identified were Escherichia coli (n = 10), Tatumella ptyseous (n = 4), Acinetobacter baumannii (n = 2), and Klebsiella pneumoniae (n = 1). The isolates were all resistant to at least three antimicrobial classes. All the isolates were resistant to the bac¬tericidal action of the serum, while 2 (11.8%) were hemolytic on blood agar. Conclusion: Adequate veterinary examination of slaughtered cattle before presenting for slaugh¬ter is imperative to reduce the contamination of the meat and environment with the urine of cattle with elevated levels of bacteriuria.