Direct Microscopic Counts Research Articles

Effect of zinc oxide/graphene oxide nanocomposites on the cytotoxicity, antibacterial and mechanical properties of polymethyl methacrylate

BackgroundEnhancing the antibacterial properties of polymethyl methacrylate (PMMA) dental resins is crucial in preventing secondary infections following dental procedures. Despite the necessity for such improvement, a universally applicable method for augmenting the antibacterial properties of PMMA without compromising its mechanical properties and cytotoxicity remains elusive. Consequently, this study aims to address the aforementioned challenges by developing and implementing a composite material known as zinc oxide/graphene oxide (ZnO/GO) nanocomposites, to modify the PMMA.MethodsZnO/GO nanocomposites were successfully synthesized by a one-step procedure and fully characterized by TEM, EDS, FTIR and XRD. Then the physical and mechanical properties of PMMA modified by ZnO/GO nanocomposites were evaluated through water absorption and solubility test, contact angle test, three-point bending tests, and compression test. Furthermore, the biological properties of the modified PMMA were evaluated by direct microscopic colony count method, crystal violet staining and CCK-8.ResultsThe results revealed that ZnO/GO nanocomposites were successfully constructed. When the concentration of nanocomposites in PMMA was 0.2 wt. %, the flexural strength of the resin was increased by 23.4%, the compressive strength was increased by 31.1%, and the number of bacterial colonies was reduced by 60.33%. Meanwhile, It was found that the aging of the resin did not affect its antibacterial properties, and CCK-8 revealed that the modified PMMA had no cytotoxicity.ConclusionZnO/GO nanocomposites effectively improved the antibacterial properties of PMMA. Moreover, the mechanical properties of the resin were improved by adding ZnO/GO nanocomposites at a lower range of concentrations.

Antifungal activity test of nanosilver in serum cosmetic preparations

Serum is one of the cosmetic products that people often use today. Along with the times and technological developments, innovations in serum products are also increasing with the addition of active ingredients. Nanosilver is one of the nanotechnology findings and is known as a good antifungal. In this study, serum products were made with the addition of nanosilver as an antifungal, with variations in the acquisition of 20 ppm nanosilver by 5, 10, and 15%. This study aims to determine the characteristics of nanosilver synthesized using UV-Vis Spectrophotometer and TEM, determine the physical and chemical characteristics of nanosilver serum preparations, and determine the antifungal activity of nanosilver in serum cosmetic preparations. In this study, the synthesis of nanosilver using a chemical reduction method with sodium citrate as a reducing agent and stabilizer. Characterization of nanosilver with UV-Vis Spectrophotometer showed that the synthesized nanosilver was relatively stable, and the results of description with TEM showed that the nanosilver produced was on the nanoscale with an average diameter of 35.075 nm and spherical shape. The physical and chemical characteristics of the serum preparation carried out by organoleptic testing showed that the five samples were homogeneous, non-irritating, and had a pH of 6. Testing of nanosilver antifungal activity was carried out by the DMC (Direct Microscopic Count) method with direct counting techniques under a microscope for eight weeks. Based on the calculation results, from week 0 to week 8, it shows that the serum preparation with the addition of nanosilver can inhibit fungi with the growth of the number of hyphae in F1, F2, F3, F4, F5 respectively 24.25; 22.25; 3.25; 3; and 2.75%.

Deciphering environmental factors influencing phytoplankton community structure in a polluted urban river

Tuojiang River Basin is a first-class tributary of the upper reaches of the Yangtze River—which is the longest river in China. As phytoplankton are sensitive indicators of trophic changes in water bodies, characterizing phytoplankton communities and their growth influencing factors in polluted urban rivers can provide new ideas for pollution control. Here, we used direct microscopic count and environmental DNA (eDNA) metabarcoding methods to investigate phytoplankton community structure in Tuojiang River Basin (Chengdu, Sichuan Province, China). The association between phytoplankton community structure and water environmental factors was evaluated by Mantel analysis. Additional environmental monitoring data were used to pinpoint major factors that influenced phytoplankton growth based on structural equation modeling. At the phylum level, the dominant phytoplankton taxa identified by the conventional microscopic method mainly belonged to Bacillariophyta, Chlorophyta, and Cyanophyta, in contrast with Chlorophyta, Dinophyceae, and Bacillariophyta identified by eDNA metabarcoding. In α-diversity analysis, eDNA metabarcoding detected greater species diversity and achieved higher precision than the microscopic method. Phytoplankton growth was largely limited by phosphorus based on the nitrogen-to-phosphorus ratios > 16:1 in all water samples. Redundancy analysis and structural equation modeling also confirmed that the nitrogen-to-phosphorus ratio was the principal factor influencing phytoplankton growth. The results could be useful for implementing comprehensive management of the river basin environment. It is recommended to control the discharge of point- and surface-source pollutants and the concentration of dissolved oxygen in areas with excessive nutrients (e.g., Jianyang–Ziyang). Algae monitoring techniques and removal strategies should be improved in 201 Hospital, Hongrihe Bridge and Colmar Town areas.

Antifungal activity test of nanosilver combination with lip balm cosmetic preparation

Nanosilveris is a silver-based material with nanometer particle sizes (1-100 nm) predicted to be antifungal or an alternative to preservatives in lip balm preparations that are biocompatible. The nanosilver synthesis process in this study used the bottom-up method by adding sodium citrate as a reducing agent and stabilizer. This study aimed to determine the characteristics of the results of 20 ppm nanosilver synthesis using a UV-Vis and TEM spectrophotometer and to determine the antifungal activity of nanosilver in lip balm cosmetic preparations. Variations in adding 20 ppm nanosilver into lip balm preparations are 5%, 10%, and 15%. The results of characterization using a UV-Vis spectrophotometer, namely 20 ppm nanosilver, were quite stable in storage for 2 months, and the results of characterization using TEM also showed that the formed nanosilver remained stable with a nanometer size range ranging from 11.42 nm to 43.95 nm. The antifungal activity test was carried out using the Direct Microscopic Count (DMC) method by counting directly under a microscope. Based on the data obtained, it shows that the antifungal activity of the combination of nanosilver and lip balm preparations is almost equivalent to the antifungal activity of parabens. It has produced lip balm preparations with nanosilver. This is indicated by the value of the inhibition rate (%). The inhibition of fungal growth produced by lip balm preparations with parabens is almost the same as the inhibition rate (%) produced by lip balm preparations with nanosilver. The inhibition rate of lip balm preparations with parabens was 89.11%. In comparison, the inhibition rate of lip balm preparations with a nanosilver concentration of 15% was 82.31%, so it can be concluded that nanosilver has good antifungal activity and is biocompatible so that nanosilver can be used as an alternative to paraben preservatives.

Combined Black Phosphorus Nanosheets with ICG/aPDT is an Effective Anti-Inflammatory Treatment for Periodontal Disorders.

Antibacterial photodynamic treatment (aPDT) has indispensable significance as a means of treating periodontal disorders because of its extraordinary potential for killing pathogenic bacteria by generating an overpowering amount of reactive oxygen species (ROS). The elevated ROS that may result from the antibacterial treatment procedure, however, could exert oxidative pressure inside periodontal pockets, causing irreparable damage to surrounding tissue, an issue that has severely restricted its medicinal applications. Accordingly, herein, we report the use of black phosphorus nanosheets (BPNSs) that can eliminate the side effects of ROS-based aPDT as well as scavenge ROS to produce an antibacterial effect. The antibacterial effect of ICG/aPDT was observed by direct microscopic colony counting. A microplate reader and confocal microscope enabled measurements of cell viability and the quantification of ROS fluorescence. BPNS administration regulated the oxidative environment. IL-1β, IL-6, TNF-α, IL-10, TGF-β, and Arg-1 mRNA expression levels were used to assess the inflammatory response after BPNS treatment. In vivo, the efficacy of the combination of BPNSs and ICG/aPDT was evaluated in rats with periodontal disease by histomorphometric and immunohistochemical analyses. The CFU assay results verified the antibacterial effect of ICG/aPDT treatment, and ROS fluorescence quantification by CLSM indicated the antioxidative ability of the BPNSs. IL-1β, IL-6, TNF-α, IL-10, TGF-β, and Arg-1 mRNA expression levels were significantly decreased after BPNS treatment, confirming the in vitro anti-inflammatory effect of this nanomaterial. The histomorphometric and immunohistochemical analyses showed that the levels of proinflammatory factors decreased, suggesting that the BPNSs had anti-inflammatory effects in vivo. Treatment with antioxidative BPNSs gives new insights into future anti-inflammatory therapies for periodontal disease and other infection-related inflammatory illnesses and provides an approach to combat the flaws of aPDT.

Comparison of California mastitis test and Draminski mastitis detector as on-farm methods for monitoring udder health in lactating buffalo

This study was conducted to compare the performance of the California Mastitis Test (CMT) and Draminski Mastitis Detector (DMD) for monitoring udder health in lactating buffalo. A total of 647 milk samples collected from 145 apparently healthy lactating buffalo cows during the first three months of the lactation period were used in this study. Both DMD and CMT were performed on-farm directly after sampling of the milk. The diagnostic accuracy of CMT and DMD was evaluated by estimating the area under the Receiver-Operating Characteristic curve (AUC) based on a value of 200,000 somatic cells per mL as a cut-point value for an infected quarter detected by direct microscopic somatic cell count. Data analysis showed that 63.76% of CMT results were “Trace” and 99% of DMD readings were greater than 300. The accuracy of CMT and DMD was close to each other; the AUC was 80.1% and 81.4% for CMT and DMD, respectively. The optimal cut-point value for CMT was Trace (T), and 515 for DMD. In conclusion, both CMT and DMD are practical on-farm tests for identifying infected udder in buffalo cows, and the suggested cut-point value for DMD is 515 for buffalo’s milk testing instead of the 300 that was assigned by the manufacturer for cow’s milk.

Alterations in the Hemato-biochemical, Endocrine, Somatic Cell Count and Milk Composition in Lactating Tarai Buffaloes during Different Lactation Stages

Background: Tarai buffalo is indigenous buffalo breed of Uttarakhand state, dual purpose, well adapt to hot-humid climatic condition of Tarai area. This study aimed to evaluate the alterations in the hemato-biochemical, endocrine, milk somatic cell count and milk composition in lactating Tarai buffaloes. Methods: Thirty-six healthy Tarai buffaloes were selected from four different Gujjar farms and divided into four groups consisting nine buffaloes in each group as early (60±30 days), mid (120±30 days) and late (180±30 days) lactation stages and dry buffaloes. Both blood and milk samples were collected once from each lactation stage of selected animals. Hematological parameters and milk composition were evaluated by standard procedures and methods. Biochemical and endocrine parameters were evaluated using commercially available kits as per manufacturer’s protocol. Milk somatic cell count (SCC) was done by direct microscopic counts using Newman Lampert stain. Result: It observed significantly (p less than 0.05) higher TLC value but lower plasma glucose, cholesterol, calcium, phosphorus and urea levels during early lactation stage. Significantly (p less than 0.05) declined in plasma total protein during late lactation stage and triglyceride in dry cows. Plasma hormone significantly (p less than 0.05) higher in cortisol during early lactation while higher T4 and insulin in late lactation stages. Milk fat, urea and total solids were significantly (p less than 0.05) decreased during early lactation and again increased during late lactation while milk SCC significantly (p less than 0.05) higher during early and late lactation stages.

Precipitation changes, warming, and N input differentially affect microbial predators in an alpine meadow: Evidence from soil phagotrophic protists

Soil phagotrophic protists are highly abundant and play a vital role in nutrient cycling through feeding on microbes. Global change factors, individually or in combination, often affect soil bacteria and fungi, but whether and how the resulting changes may cascade to affect phagotrophic protists remain largely unknown. Combining direct microscopic counting and high-throughput sequencing of 18s rRNA gene, we examined effects of precipitation changes, warming and nitrogen (N) input on soil phagotrophic protists in a 3-yr manipulation experiment with a Tibetan alpine meadow. Precipitation addition (+30%) enhanced but precipitation reduction (−30%) and warming decreased the alpha diversity of phagotrophic protists, primarily through altering soil moisture. However, N input (12 g N m−2 y−1) increased protist abundance, and in particular, offset the negative effect of precipitation reduction on the relative abundance of phagotrophic protists through increasing the microbial biomass, implying a bottom-up trophic control. Together, these findings indicate that interactions of multiple global change drivers may affect soil protist communities directly by modifying the soil physiochemical environment and indirectly through trophic cascading, which have implications for the potential changes in their ecosystem functions in alpine meadow under future global change scenarios.

Somatic cell counts and bacteria in milk from two nomadic herds in Abeokuta, Nigeria

Mastitis, the inflammation of the mammary gland, is a major endemic disease affecting dairy production worldwide. Costs of treatment and control of mastitis contributes to major losses to the dairy industry especially if the condition is not promptly and accurately diagnosed, thus necessitating the engagement of regular and reliable means of recognising intra-mammary infections. Somatic cell counting, which has been recognized as a major standard for mastitis diagnosis in milk, was utilized in this study as a direct measure of intramammary inflammation (IMI), along with bacterial culture and isolation to establish the presence of mammary infections in cows from two nomadic herds. Milk from all four quarters (composite samples) of each of 100 cows at various stages of lactation, were obtained and subjected to Levowitz-Weber staining of duplicate smears and direct microscopic counting of somatic cells. Culture and isolation of sterile milk swabs and subsequent identification by morphology, gram staining and biochemical tests were employed to assess the presence of mastitis-causing pathogens in the samples. Using ≤100,000 cells/ml as cut off for non-mastitic milk, sub-clinical mastitis (SM), was determined in 70 (70%) of the examined samples. Contagious pathogens, namely; Staphylococcus aureus, Staphylococcus species and others as well as environmental bacteria, E. coli and Enterococcus species amongst others, were isolated from the samples. This result circuitously indicates the level of losses to dairy production through poor milk quality and yield, costs of treatment and culling obtainable in the nomadic dairying venture. The need for routine evaluation of raw milk and other dairy products emanating from the itinerant pastoralists, using sensitive and reliable parameters to facilitate prompt diagnosis, targeted treatment and rapid control of cow to cow or herd to herd spread of IMI is highlighted in this study.

Effects of different culture media on growth of Treponema spp. isolated from digital dermatitis

Digital dermatitis (DD) lesions in cattle are characterized by the presence of multiple Treponema species. Current culture media for isolating treponemes generally uses serum supplementation from different animals to target particular Treponema sp.; however, their suitability for DD Treponema isolation has not been fully determined. We studied the effect of culture media (OTEB, NOS and TYGV) and serum supplementation on mixed Treponema spp. dynamics. Bacterial growth was evaluated by direct microscopic count, optical density, wet weight and a species-specific qPCR and the correlations between these independent methods were calculated. Wet weight, optical density and bacterial count correlated best with each other. Different Treponema species performed differently under the tested culture media. T. phagedenis growth was enhanced in OTEB media supplemented with bovine fetal serum (BFS) or horse serum (HS). T. medium had lower generation time when culture media were supplemented with rabbit serum (RS). Lowest generation time for T. pedis and T. denticola were obtained in NOS media supplemented with HS and OTEB media supplemented with BFS, respectively. Detection of cystic forms observed after 5 days of culture did not differ among the culture media. Correlation between different Treponema spp. growth quantification techniques indicated that alternative quantification methods such as qPCR and wet weight could be used depending on the purpose. We conclude that effects of culture media and serum supplementation on mixed Treponema spp. communities should be taken into account when isolating a specific Treponema species.

COMPOSITION AND QUALITY OF FRESH COW MILK OFFERED FOR SALE IN PARTS OF PLATEAU STATE OF NIGERIA.

The gross composition and quality of fresh cow milk purchased from Fulani milk vendors in three locations of Plateau State were investigated. Milk quality was assessed by the methylene blue reduction test while bacterial contamination was by the agar plate count and the direct microscopic count. The mean contents of total solids, butterfat, protein and ash of a total of 100 samples from Barkin Ladi, Jos and Bukuru markets were 12.45, 4.77, 3.90, 0.92; 12.85, 4.50, 3.68, 0.93; and 12.41, 5.26, 3.72, 0.91% respectively. The proximate constituents did not differ significantly between locations. The methylene blue test indicated that only 23.5% of the sample were of good quality while 41.2 and 35.3% were rated fair and poor respectively. No sample merited excellent rating. The agar plate count showed a range of 1.97 x 106 for Bukuru to 2.54 x 106 cells/ml for Jos market. The direct microscopic count showed the highest mean bacteria value for Barkin Ladi samples. The high bacterial counts as observed were probably indicative of poor milking hygiene and handling. It is suggested that such milk should be properly pasteurized before consumption and delivered/marketed early at source to reduce the time for microbial multiplication.

The microbial community, its biochemical potential, and the antimicrobial resistance of Enterococcus spp. in Arctic lakes under natural and anthropogenic impact (West Spitsbergen)

The sustainable management of small human communities in the Arctic is challenging. In this study, both a water supply system (Lake 1) under the natural impact of a bird-nesting area, and a wastewater receiver (Lake 2) were analysed in the vicinity of the Polish Polar Station on West Spitsbergen. Microbial community composition, abundance and activity were assessed in samples of the treated wastewater, lake water and sediments using next-generation sequencing and direct microscope counts. Special attention was given to the faecal indicator, Enterococcus spp., whose occurrence and antimicrobial resistance were tested in water and wastewater samples. The results indicate that Lake 1, at a tundra stream discharge (L-TS) and a water supply point (L-WS) were dominated by three phyla: Proteobacteria (57–58%) Bacteroidetes (27–29%) and Actinobacteria (9–10%), showing similar microbial composition up to the genus level. This suggests that nutrient-rich runoff from the bird colony was retained by surrounding tundra vegetation and reached Lake 1 at L-TS to a limited extent. Lake 2, being the wastewater recipient (WW-R), mirrors to some extent the core phyla of treated wastewater (WW-E), but in different shares. This suggests the possible washout of wastewater-related bacteria with activated sludge flocs, which was also supported by the microscopic observations. Compared to Lake 1, in WW-R an increase in all tested parameters was noted: total prokaryotic cell number, average cell volume, prokaryotic biomass and live cell percentage. The presence of Enterococcus spp. antibiotic resistance patterns highlight the importance of human associated microbiome and resistome dissemination via wastewater discharge. Moreover, it can be expected that temperature-related biochemical processes (e.g. nutrient cycling) may be accelerated by the ongoing climate change. Thus, proper wastewater treatment requires locally adapted solutions in increasingly visited and inhabited polar regions. Additionally, microbial community discharged to the environment with the treated wastewater, requires critical attention.

Relationships of Alizarin Test Scores with Somatic Cell Count in Bovine Milk

The aim of this study was to reveal the association of alizarin test scores (ATS) with somatic cell scores (SCC) in bovine milk. The milk samples (n=60) were collected from three milk selling points in Samsun province of Turkey in two test days (TD). To obtain ATS, change of colour in milk after adding dye solution were used (ATS 1: red-brown/normal, ATS 2: yellow/acidic, and ATS 3: violet/alkali). To test for reliability of ATS by acidity, pH values of the samples were measured with a standard pH meter. In SCC analyses, direct microscopic cell counting was applied. Of examined parameters, only SCC was differed by TD, and both pH and SCC were differed by the location. According to ATP groups, pH and SCC means were also changed. Finally, estimated weak (r=0.247) correlation coefficient between ATS and SCC pointed out that ATS data are not suitable to detect quality degree of bovine milk samples.

Using direct epifluorescent microscopic count for rapid enumeration of viable yeast and bacteria in injured conditions

Traditional method for assessing cell count requires an incubation period of 2-3 days. The direct microscopic count (DMC) method gives rapid enumeration of yeast and bacteria. However, the application is limited, since it is not possible to distinguish accurately between viable and nonviable cell. In this report, several nucleic acid dyes from Molecular Probe Inc. were used to stain the cells for enumeration of live and dead yeast in injured conditions, in which the dye can stain the DNA of nucleus and mitochondria, which then fluoresce yellow under fluorescence microscope, as well as stain the cytoplasm of actively growing cells to fluoresce green, while the cytoplasm of inactive cells fluoresced orange. The direct microscopic count multiplied by the live cell count ratio obtained by this direct epifluoroscent microscopic count (DEMC) method gives the estimated viable yeast count. According to our results, the correlation coefficient (R2) between the cell count obtained by the DEMC method and that by the standard plate count was 0.91 for yeast and 0.96 for bacteria in frozen and heating conditions, respectively. Requiring only 30 min, this method can also be used for the rapid enumeration of viable bacteria in injured conditions.

Preliminary verification studies of the motility and fluorescence assay (MFA) for ballast water quality monitoring

The International Maritime Organization (IMO) has adopted a ballast water convention to prevent spread of invasive species with ballast water and with it comes the need for fast and reliable tests to estimate the number of viable organisms found in ballast water.During 2017 and 2018, computer-assisted automatic quantification of plankton was compared with direct microscopic counts. Analysed samples represented simulations of ballast water samples from Denmark. Samples consisted of live plankton monocultures, mixed cultures, or ambient organisms from local seawater. The aim was to validate the performance and efficiency of the automated Motility and Fluorescence Assay (MFA) system BallastWISE, which automatically counts motile and fluorescent organisms in the fractions ≥10 - <50 μm and ≥ 50 μm, according to the ballast water discharge standard.Standardized counting methods for comparison were completed under microscope. Organisms in the ≥10 - <50 μm size range were analysed using an FDA (Fluorescein diacetate) and CMFDA (5-chloromethylfluorescein diacetate) staining method, and a standard movement and response to stimuli technique was used for the ≥50 μm size range.BallastWISE results correlated well with direct microscopic counts, showing promising counting performance and efficiency when it comes to rapid analysis of ballast water plankton samples. Quantification of monoculture and mixed cultures using BallastWISE correlated well with manual viable counts (Tetraselmis suecica in size range ≥ 10 - <50 μm: Pearson correlation (r) = 1.0; Tigriopus californicus and Brachionus plicatilis in size range ≥ 50 μm: r = 0.99). BallastWISE counts also correlated well with viable microscopic counts of ambient organisms in natural seawater (size range ≥ 10 - <50 μm: r = 0.97 and size range ≥ 50 μm: r = 0.89). We propose that computer-assisted quantification of plankton provides a rapid and precise alternative to traditional counting and identification of organisms in water samples such as ballast water.

The Effect of TEAT PROTECT spray and potassium permanganate teat dip in curing subclinical mastitis in crossbred cows of Villupuram district of Tamilnadu

A study was undertaken to assess the incidence of subclinical mastitis in crossbred cows of Villupuram district by using direct microscopic Somatic cell count (SCC). For this purpose sixty eight crossbred cows positive for subclinical mastitis (SCM) as per IDF (International Dairy Federation) criteria were randomly allotted in to two treatment groups. The cows in T1 group were subjected to post milking teat dip with one per cent Potassium permanganate (KMnO4) solution immediately after milking. The cows in T2 group were sprayed with TEAT PROTECT sprays. Sixteen healthy cows were kept as control group and udder was washed with plain water. The treatments were carried out for 30 days. Udder health status was determined by recording the parameters viz. somatic cell count (SCC), average daily milk yield, udder colony count and teat colony count. The results revealed that TEAT PROTECT spray is superior to Potassium permanganate in curing SCM of crossbred cows.

Phage Particles in Ground Arctic Ice

This is the first report on investigation of bacteriophages in ancient Arctic ground ice of various genesis and geological age. Electron microscopy revealed phage particles in all ice samples. Tailed bacteriophages were the dominant morphotype. A correlation was found between abundances of intact microbial cells and phage particles. Direct microscopic counts revealed the highest phage abundance melted native samples of ice wedge. Dependence of occurrence and abundance of phage particles on genesis of ground ice was observed. The phages, as an integral component of microbial communities, were found to be preserved in extreme low-temperature conditions of ground ancient ice.

Development and validation of BLRI Mastitis Test Kit at Bangladesh Livestock Research Institute Regional Station, Sirajganj.

Objective:The objective of this study was to develop a low-cost kit for the detection of subclinical mastitis (SCM) and to check its validity, reproducibility, and efficacy at the field level.Materials and Methods:A total of 550 quarter milk samples from crossbred dairy cows were collected, of which 400 milk samples were used to validate the newly developed BLRI mastitis test (BMT) kit to justify its efficacy as an individual test kit in detecting SCM based on somatic cell count (SCC) by direct microscopic count (DMC). The efficacy of the newly developed BMT was compared with the California Mastitis Test (CMT) kit. Another 150 milk samples were subjected to SCC determined by DMC and DCC (De Laval cell counter®) categorized by CMT and BMT scores.Results:A SCM test kit, namely, BMT kit was successfully developed in this study. The percentage accuracy of CMT and BMT were 76.75% and 75.75%; sensitivity 69.36% and 67.56%; specificity 85.95% and 85.85%; positive predictive value 86.03% and 85.71%; negative predictive value 69.23% and 68%, respectively. A p value of 0.001 was found for both CMT and BMT. However, CMT and BMT had no significant difference in sensitivity (p = 0.778). Average SCCs (cells/ml) determined by DCC and DMC, respectively, were mostly corresponded to the SCC ranges of both CMT and BMT scores.Conclusion:The newly developed BMT kit is an independent, cheap, farmer-friendly, first country made, and reliable SCM diagnostic test kit that can be used at field condition.

Detection of Escherichia coli O157:H7 and Salmonella enterica serotype Typhimurium based on cell elongation induced by beta-lactam antibiotics.

Pathogenic bacteria such as Shiga toxigenic Escherichia coli and Salmonella can cause severe food-borne diseases. Rapid and sensitive detection of these foodborne pathogens is essential to ensure food safety. In this study, a novel method based on cell elongation induced by beta-lactam antibiotics for direct microscopic counting of Gram-negative bacteria was established. Combined with the sample preparation steps of membrane filtration and magnetic separation, the detection of E. coli O157:H7 and Salmonella enterica serotype Typhimurium was achieved by direct optical microscopic counting of the number of elongated bacteria. The limit of detection of E. coli O157:H7 and S. typhimurium could reach 20 CFU mL-1. The recovery tests for E. coli O157:H7 and S. typhimurium in water and milk samples showed acceptable recovery values between 93.6% and 106.2%. This method is sensitive, cost effective, and rapid (<2 h) and shows great potential for the detection of Gram-negative pathogens in various environmental and food samples.

Changes in airborne fungal flora along an urban to rural gradient

Exposure to bioaerosols has been associated with respiratory allergies and asthma. This highlights a need to characterize the fungal flora along an urbanization gradient. In this study, the airborne fungal flora, the concentration of dominant fungi and their seasonal variation along an urbanization gradient were investigated through viable count and direct microscopic count. Thirty-one fungal species including Cladosporium, Aspergillus, Penicillium, Fusarium and Trichoderma were identified. Characteristics of fungal floras differed significantly among seasons. The lowest spore concentration presented in winter, constituting the baseline data of airborne fungi. Urban and rural areas had significantly different airborne fungal floras and spore concentration. Aspergillus flavus and C. oxysporum were the dominant fungi in summer and autumn, respectively. Spatial distributions of dominant fungi, A. flavus and C. oxysporum, in their dominant seasons were similar and in both cases their spore concentration increased along a gradient of vegetation coverage. This pattern seems to be a result of the relatively lower plant tissue and soil in the urban. Contrasting with the dominance of allergenic C. herbarum in temperate areas, the dominant fungus in tropical Taiwan was C. oxysporum.