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In this study, a pretreatment method based on a magnetic capture probe for the rapid isolation and enrichment of bacteria from raw pork was developed. The chitosan immobilized Fe3O4@MIL-100(Fe) was prepared as a capture probe for total bacterial counts through the electrostatic interaction of positively charged chitosan and the negatively charged substances on the surface of bacteria. The interference of matrix in pork samples on this method was studied and removed by differential centrifugation. The results showed the capture probe had a great selectivity binding and magnetic separation properties for the tested six common bacteria in pork. Under the optimal conditions, the capture efficiency of the bacteria (105 CFU mL-1) from pork surface samples was all above 90%. The capture efficiency of the bacteria in a homogenate system was greatly decreased due to the interference of sarcoplasmic protein and myofibrillar protein in pork. The matrix effect was mitigated by a differential centrifugation method, and the capture efficiency of all six bacteria was >80%. The developed magnetic separation method took 40 min and showed good isolation and enrichment properties of bacteria. Thus, the proposed method is expected to provide a simple, convenient, and time-saving pretreatment method for the detection of total bacterial counts in pork.

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Measuring the abundance of microbes in a sample is a common procedure with a long history, but best practices are not well-conserved across microbiological fields. Serial dilution methods are commonly used to dilute bacterial cultures to produce countable numbers of colonies, and from these counts, to infer bacterial concentrations measured in colony-forming units (CFUs). The most common methods to generate data for CFU point estimates involve plating bacteria on (or in) a solid growth medium and counting their resulting colonies or counting the number of tubes at a given dilution that have growth. Traditionally, these types of data have been analyzed separately using different analytic methods. Here, we build a direct correspondence between these approaches, which allows one to extend the use of the most probable number method from the liquid tubes experiments, for which it was developed, to the growth plates by viewing colony-sized patches of a plate as equivalent to individual tubes. We also discuss how to combine measurements taken at different dilutions, and we review several ways of analyzing colony counts, including the Poisson and truncated Poisson methods. We test all point estimate methods computationally using simulated data. For all methods, we discuss their relevant error bounds, assumptions, strengths, and weaknesses. We provide an online calculator for these estimators.Estimation of the number of microbes in a sample is an important problem with a long history. Yet common practices, such as combining results from different measurements, remain sub-optimal. We provide a comparison of methods for estimating abundance of microbes and detail a mapping between different methods, which allows to extend their range of applicability. This mapping enables higher precision estimates of colony-forming units (CFUs) using the same data already collected for traditional CFU estimation methods. Furthermore, we provide recommendations for how to combine measurements of colony counts taken across dilutions, correcting several misconceptions in the literature.

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Enterococcus faecalis is among the most resistant bacteria found in infected root canals. The demand for cutting-edge disinfection methods has rekindled research on photoinactivation with visible light. This study investigated the bactericidal activity of femtosecond laser irradiation against vancomycin-resistant Enterococcus faecalis V583 (VRE). The effect of parameters such as wavelength and energy density on the viability and growth kinetics of VRE was studied to design an optimized laser-based antimicrobial photoinactivation approach without any prior addition of exogenous photosensitizers. The most effective wavelengths were 430 nm and 435 nm at a fluence of 1000 J/cm2, causing a nearly 2-log reduction (98.6% and 98.3% inhibition, respectively) in viable bacterial counts. The colony-forming units and growth rate of the laser-treated cultures were progressively decreased as energy density or light dose increased at 445 nm but reached a limit at 1250 J/cm2. At a higher fluence of 2000 J/cm2, the efficacy was reduced due to a photobleaching phenomenon. Our results highlight the importance of optimizing laser exposure parameters, such as wavelength and fluence, in bacterial photoinactivation experiments. To our knowledge, this is the first study to report an optimized wavelength for the inactivation of VRE using visible femtosecond laser light.

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Heterotrophic bacteria are commonly found in water samples. While these Heterotrophic Bacterial/Plate Counts (HPC) do not necessarily indicate a health hazard, high counts provide a good indication of the efficiency of water disinfection and integrity of distribution systems. The aim of this study was to compare the PetrifimTM AC method to the pour plate technique for the testing of HPC in water samples. Artificially contaminated (192 samples) and natural water samples (25) were processed using two methods. Both methods accurately detected high, medium and low counts of HPC, producing average Z scores between -2 and +2. Paired-wise student t-test and correlation coefficient showed nonsignificant differences between the results of two methods. Acceptable repeatability and reproducibility was obtained using both the methods. Uncertainty of measurement for PetrifilmTM AC and pour plate method was found to be 2.9% and 5.4%, respectively. PetrifilmTM AC proved to be robust at 33°C and 37°C. In conclusion, PetrifimTM AC, which is easy to process, read, and less time consuming, proved to be comparable to the conventional pour plate method in establishing HPC in water. In addition, PetrifimTM AC requires less space for the processing and incubation, generate small volume of waste for disposal, and requires no equipment, except for the incubator.

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BACKGROUND: Oral care is important in preventing aspiration pneumonia in older adults. However, it is not clear what kind of oral care can reduce the number of bacteria in saliva. The purposes of this study are to clarify whether there is a relationship between plaque amounts and salivary bacterial counts, and how bacteria dispersed into the oral cavity by brushing can be reduced. METHODS: First, saliva samples were collected from 10 healthy adult volunteers after 30 h of unbrushing and after thorough brushing, and the total bacterial count was determined by real-time PCR. Next, 40 older adults attending an outpatient dental clinic were randomly assigned into two groups: a wiping group (20 patients) and a mouthwashing group (20 patients). Saliva was collected before and after brushing, and after wiping in the wiping group and after mouthwashing in the mouthwashing group, and the total bacterial count was quantified by real-time PCR. RESULTS: In a study of volunteers, there was no association between plaque amounts and salivary bacterial counts. In a study of older adult patients, salivary bacterial counts were significantly higher in patients with higher oral hygiene index and fewer remaining teeth. Brushing increased salivary bacterial counts. Wiping did not significantly reduce the number of bacteria, while mouthwash returned the increased number of bacteria after brushing to the pre-brushing level. CONCLUSIONS: There is no direct relationship between the amount of plaque and the number of bacteria in saliva. Brushing disperses bacteria into the oral cavity, resulting in a marked increase in the number of bacteria in saliva. Wiping does not collect the dispersed bacteria, and it seems essential to rinse the mouth after brushing. TRIAL REGISTRATION: UMIN000045854.

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Diabetes mellitus (DM) increases the susceptibility to infection. A plausible association between apical periodontitis (AP) and DM has been reported, but the underlying mechanism is not yet elucidated. AIM: To investigate the bacterial quantity and the expression of interleukin-17 (IL-17) in necrotic teeth with AP in type 2 DM (T2DM), pre-diabetic and non-diabetic control patients. METHODOLOGY: In all, 65 patients with necrotic pulp and AP [periapical index (PAI) scores ≥3] were included. The age, gender, medical history and medications list, including metformin and statin intake, were recorded. Glycated haemoglobin (HbA1c) was analysed, and the patients were divided into three groups: T2DM (n = 20), pre-diabetics (n = 23) and non-diabetic (n = 22). Bacterial samples (S1) were collected by file and paper points. Bacterial DNA was isolated and quantified using 16S ribosomal RNA gene-targeted quantitative real-time polymerase chain reaction (qPCR). For IL-17 expression, (S2) samples were collected from the periapical tissue fluid using paper points passing through the apical foramen. The IL-17 total RNA was extracted, and reverse transcription (RT-qPCR) analysis was performed. Comparisons between the three study groups were conducted using one-way anova and Kruskal-Wallis test to explore the relationship between bacterial cell counts and IL-17 expression in each group. RESULTS: The distributions of PAI scores were equivalent among the groups, p = .289. T2DM patients had higher bacterial counts and IL-17 expression than other groups, but these differences were not statistically significant, p = .613 and p = .281, respectively. T2DM patients taking statin appear to have lower bacterial cell count than those who do not take statin, approaching the significance level, p = .056. CONCLUSION: T2DM patients had a non-significant higher bacterial quantity and IL-17 expression compared to pre-diabetic and healthy controls. Although these findings indicate a weak association, it may impact the clinical outcome of endodontic diseases in diabetic patients.

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BACKGROUND: The determination of the microbiological quality and safety of raw milk and the associated influencing factors at the farm level is very critical given that the quality or safety of subsequent products that are further produced depends on this. Therefore, this study aimed to determine the microbiological quality and safety of bulk milk and identify associated risk factors, and assess the presence/absence of S. aureus in bulk milk with potential contaminating sources in dairy farms in Asella, Ethiopia. RESULTS: The geometric means of bacterial counts in farm bulk milk were 5.25 log cfu/ml, 3.1 log cfu/ml and 2.97 log cfu/ml for total bacterial count (TBC), coliform count (CC) and coagulase-positive staphylococci count (CPS), respectively. Of the 50 dairy farms, 66, 88, and 32% had TBC, CC and CPS counts, respectively, that exceeded the standard international limits for raw cow's milk intended for direct human consumption. TBC tended to increase as CC increased in bulk milk (r = 0.5). In the final regression model, increased TBC, CC and the contamination of farm bulk milk by S. aureus were significantly associated with dirty barns, dirty cows and soiled udder and teats. TBC was higher during the rainy season than during the dry season. The reported practice of washing teats with warm water significantly decreased CC and CPS. The occurrence of S. aureus was significantly (p < 0.05) higher in bulk farm milk (42%) than in pooled udder milk (37.3%), teat swabs (22.5%), milkers' hand swabs (18%), bulking bucket swabs (16.7%), milking container swabs (14%), and water for cleaning of udder and milkers' hands (10%). The questionnaire survey result showed widespred raw milk consumption habits, low level of training and poor hygienic milking practices. CONCLUSIONS: This study revealed low-quality bulk farm milk with high bacterial counts and a high occurrence of S. aureus. This indicates the potential food safety risks due to consumption of raw milk or its products. This study suggests awareness creation to dairy farmers and the public on hygienic milk production and heat treatment of milk before consumption.

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Due to the observed climate warming, water deficiency in soil is currently one of the most important stressors limiting the size and quality of plant crops. Drought stress causes a number of morphological, physiological, and biochemical changes in plants, limiting their growth, development, and yield. Innovative methods of inducing resistance and protecting plants against stressors include the inoculation of crops with beneficial microorganisms isolated from the rhizosphere of the plant species to which they are to be applied. The aim of the present study was to evaluate 12 different strains of rhizosphere bacteria of the genera Pantoea, Bacillus, Azotobacter, and Pseudomonas by using them to inoculate strawberry plants and assessing their impact on mitigating the negative effects of drought stress. Bacterial populations were assessed by estimates of their size based on bacterial counts in the growth substrate and with bioassays for plant growth-promoting traits. The physiological condition of strawberry plants was determined based on the parameters of chlorophyll fluorescence. The usefulness of the test methods used to assess the influence of plant inoculation with rhizosphere bacteria on the response of plants growing under water deficit was also evaluated. A two-factor experiment was performed in a complete randomization design. The first experimental factor was the inoculation of plant roots with rhizosphere bacteria. The second experimental factor was the different moisture content of the growth substrate. The water potential was maintained at -10 to -15 kPa under control conditions, and at -40 to -45 kPa under the conditions of water deficit in the substrate. The tests on strawberry plants showed that the highest sensitivity to water deficiency, and thus the greatest usefulness for characterizing water stress, was demonstrated by the following indices of chlorophyll "a" fluorescence: FM, FV, FV/FM, PI, and Area. Based on the assessment of the condition of the photosynthetic apparatus and the analysis of chlorophyll "a" fluorescence indices, including hierarchical cluster analysis, the following strains of rhizosphere bacteria were found to have favorable effects on strawberry plants under water deficit: the Bacillus sp. strains DLGB2 and DKB26 and the Pantoea sp. strains DKB63, DKB70, DKB68, DKB64, and DKB65. In the tests, these strains of Bacillus sp. exhibited a common trait-the ability to produce siderophores, while those of Pantoea sp. were notable for phosphate mobilization and ACCD activity.

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Objectives: The study was undertaken to evaluate the influences of some physicochemical parameters and viable bacterial counts in cultured ponds (water and sediment) on the viable counts of the Pangasius catfish (Pangasianodon hypophthalmus) (gill and intestine) on a seasonal scale. Materials and Methods: Physicochemical parameters, viz., ambient temperature, water temperature, water transparency, pH of the pond waters, and viable bacterial counts of pond water, sediment, fish gills, and intestines, were monitored during four different seasons. The responses of viable counts of bacteria to the seasonal changes of physicochemical parameters were also assessed using redundancy analysis (RDA) and a heatmap coupled with the clustering analysis. Results: Except for fluctuations in air and water temperatures, the other two physicochemical parameters were almost stable throughout the study periods. The gills and water counts were relatively lower than those of the intestine and sediment. Pearson's correlation analysis established no significant correlations between the physicochemical parameters and viable bacterial counts. However, significant positive correlations were detected between the viable counts of water and sediment and between the gill and intestine. The RDA plot showed that, except in spring, the viable counts of a particular sample type were similar among the four locations. The results of permutation test showed that, individually none of the studied physicochemical parameters was significant; however, the seasons significantly affected the viable counts.

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OBJECTIVES: Mouth breathing is a key feature of obstructive sleep apnea (OSA). The current study evaluated dental, salivary and orthodontic characteristics of children with OSA, and compared them to those of children without OSA. MATERIALS AND METHODS: Twenty-two children (mean age 5.3 years, 13 males) with OSA and 21 children without OSA who served as a control group (mean age 6.8 years, 11 males) underwent dental examinations. The OSA group was classified according to the apnea-hypopnea Index. Clinical examination included plaque index, gingival index, caries status, pH at 7 oral sites, salivary carries bacterial counts and inflammatory cytokine levels. Orthodontics measurements were calculated as the percentage of children with values in the normal range, in each group. RESULTS: The mean values of the decayed, missing and filled teeth (DMFT)/dmft index, the gingival index and the plaque index were higher in the OSA than the control group. Salivary Mutans streptococci and lactobacilli counts were significantly higher in the OSA than the control group; as were pH values in the hard and soft palate, and in the posterior and middle tongue. Significantly lower values were observed in the OSA than the control group for most of the orthodontic variables examined. Similarly, stratification of AHI according to severity shows the lowest values among those with mild OSA, and the highest among those with severe AHI. CONCLUSIONS: Compared to a control group, mouth breathing children with obstructive sleep apnea had differences in oral microbiota, greater acidity and poorer dental status. CLINICAL RELEVANCE: Clinicians should be aware of the various oral disturbances that may accompany OSA, and implement preventive measures.

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Finafloxacin is a novel fluoroquinolone with optimal antibacterial activity in low pH environments, therefore offering a therapeutic advantage over some traditional antibiotics, in treating bacterial infections associated with acidic foci. Coxiella burnetii, the causative agent of Q fever, is a bacterium which resides and replicates in acidic intracellular parasitic vacuoles. The efficacy of finafloxacin was evaluated in vivo using the A/J mouse model of inhalational Q fever and was compared to doxycycline, the standard treatment for this infection and ciprofloxacin, a comparator fluoroquinolone. Finafloxacin reduced the severity of the clinical signs of infection and weight loss associated with Q fever, but did not reduce the level of bacterial colonization in tissues compared to doxycycline or ciprofloxacin. However, histopathological analysis suggested that treatment with finafloxacin reduced tissue damage associated with C. burnetii infection. In addition, we report for the first time, the use of viable counts on axenic media to evaluate antibiotic efficacy in vivo.

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The objectives of this work were to study the prevalence and the patterns of antibiotic resistance of staphylococcal isolates from bulk-tank milk of goat herds across Greece, to assess possible associations of the presence of antibiotic resistance with the quality of milk in these herds and to evaluate herd-related factors potentially associated with the presence of antibiotic resistance among these staphylococcal isolates. A cross-sectional study was performed on 119 goat herds in Greece. Bulk-tank milk samples were collected for bacteriological examination; staphylococcal isolates were evaluated for resistance to 20 antibiotics. Oxacillin-resistant, resistant to at least one antibiotic, and multi-resistant staphylococcal isolates were recovered from 5.0%, 30.3%, and 16.0% of herds, respectively. Of 80 isolates, 7.5% were resistant to oxacillin, 50.0% were resistant to at least one antibiotic and 27.5% were multi-resistant. Resistance was seen more frequently among coagulase-negative staphylococci (59.3%) than among Staphylococcus aureus (23.8%). Resistance was more frequent against penicillin and ampicillin (41.3% of isolates) and fosfomycin (27.5%). No association was found with biofilm formation by staphylococci. For recovery of oxacillin-resistant isolates, the presence of working staff in the herds emerged as a significant factor; respective factors for the isolation of staphylococci resistant to at least one antibiotic were part-time farming and high (>10) number of systemic disinfections in the farm annually. The same three factors concurrently were also identified to be significant for the recovery of multi-resistant isolates.

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The objectives of this work were to study prevalence and characteristics of resistance to antibiotics of staphylococcal isolates from the bulk-tank milk of sheep flocks across Greece, to assess possible associations of the presence of antibiotic resistance with the quality of milk in these flocks and to evaluate flock-related factors potentially associated with antibiotic resistance among these isolates. A cross-sectional study was performed in 325 sheep flocks in Greece. Bulk-tank milk samples were collected for bacteriological examination; staphylococcal isolates were evaluated for resistance to 20 antibiotics. Oxacillin-resistant staphylococcal isolates, isolates resistant to any antibiotic, and multi-resistant isolates were recovered from 8.0%, 30.5%, and 12.0% of flocks, respectively. Of 232 isolates, 11.6% were resistant to oxacillin, 46.1% were resistant to at least one antibiotic, and 16.4% were multi-resistant. Resistance was seen more frequently among coagulase-negative (50.6%) than among Staphylococcus aureus (31.5%) isolates. Resistance was more frequent against penicillin and ampicillin (34.1% of isolates), clindamycin (17.7%), and fosfomycin (14.2%). An association was found between biofilm formation by staphylococci and resistance to fosfomycin. For recovery of oxacillin-resistant isolates, the lack of experience by farmers emerged as a significant factor; respective factors for the isolation of staphylococci resistant to any antibiotic or multi-resistant isolates were the early stage of the lactation period (0th-1st month) and the intensive management system applied in the flocks, respectively.

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INTRODUCTION: This study evaluated the relative abundance and ribosomal activity of selected bacteria in carious dentin of teeth with different pulp conditions. METHODS: Thirty healthy patients with class I occlusal caries in molars were categorized into 3 groups based on the pulp diagnosis: normal pulp (NP, n = 10) with caries extending less than half the thickness of dentin (as assessed radiographically), reversible pulpitis (n = 10), and symptomatic irreversible pulpitis (n = 10) with caries extending more than two thirds of the thickness of dentin. Carious dentin samples were collected from the deepest part of the cavity and stored in RNAlater solution (Ambion Inc, Austin, TX). Eight bacterial taxa were evaluated from the samples: Streptococcus mutans, Lactobacillus fermentum, Veillonella, Actinomyces, Rothia dentocariosa, Olsenella profusa, Prevotella intermedia, and Bifidobacterium dentium. The 16S ribosomal RNA (rRNA) gene and 16S rRNA were quantified by real-time polymerase chain reaction and used to calculate the relative genome abundance and relative ribosomal abundance. The Fisher exact test was used to compare proportions between groups. The mean rank difference between the various groups was assessed using the Kruskal-Wallis test with the Bonferroni-Holm correction. RESULTS: The reversible pulpitis group had significantly higher 16S rRNA gene and rRNA counts of Actinomyces (P < .001 and P = .002) and B. dentium (P = .005 and P = .007) relative to the NP group. The symptomatic irreversible pulpitis group had significantly higher 16S rRNA gene and rRNA counts of L. fermentum (P < .001 and P < .001), Actinomyces (P < .001 and P < .001), O. profusa (P < .001 and P < .001), P. intermedia (P = .001 and P = .002), and Bifidobacterium (P < .001 and P < .001) relative to the NP group. CONCLUSIONS: Specific bacterial activity varies in carious dentin of teeth with different pulp conditions.

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BACKGROUND: The human milk microbiome may contribute to the benefits of breastfeeding by providing bacteria to the infant gastrointestinal tract. Many women pump their milk, but the effect of pumping on the milk microbiome is unknown. OBJECTIVES: Our objective was to determine the effects of pumping supplies on the pumped human milk microbiome. METHODS: This was an in-home, randomized, crossover trial of 2 collection methods. Women (n = 52) pumped twice within 3.5 h, once with their own breast pumps and milk collection supplies (OWN SUPP) and once with a hospital-grade pump and sterile collection supplies (STER SUPP). Pumping order was randomized. The milk microbiome was characterized by aerobic culturing and 16S ribosomal RNA gene sequencing. RESULTS: Milk collected with OWN SUPP yielded more total aerobic and gram-negative bacteria than milk collected with STER SUPP, reflecting a 6.6 (adjusted OR; 95% CI: 1.7, 25; P = 0.006) higher odds of containing >104 total aerobic CFU/mL and 19 (adjusted OR; 95% CI: 4.1, 88; P < 0.0001) higher odds of yielding culturable gram-negative bacteria. Milk collected with OWN SUPP yielded more Proteobacterias , including higher relative abundances of Acinetobacter and Stenotrophomonas, compared to milk collected with STER SUPP. Results were consistent across pumping-order groups. CONCLUSIONS: We demonstrated that pumping supplies altered the milk microbiome. On average, milk collected with OWN SUPP resulted in elevated levels of culturable total and gram-negative bacteria and proteobacterial DNA compared to milk collected with STER SUPP. More research is needed to assess implications for infant health.

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OBJECTIVES: To investigate plaque inhibition of 0.1% octenidine mouthwash (OCT) vs. placebo over 5 days in the absence of mechanical plaque control. MATERIALS AND METHODS: For this randomized, placebo-controlled, double-blind, parallel group, multi-center phase 3 study, 201 healthy adults were recruited. After baseline recording of plaque index (PI) and gingival index (GI), collection of salivary samples, and dental prophylaxis, subjects were randomly assigned to OCT or placebo mouthwash in a 3:1 ratio. Rinsing was performed twice daily for 30 s. Colony forming units in saliva were determined before and after the first rinse. At day 5, PI, GI, and tooth discoloration index (DI) were assessed. Non-parametric van Elteren tests were applied with a significance level of p < 0.05. RESULTS: Treatment with OCT inhibited plaque formation more than treatment with placebo (PI: 0.36 vs. 1.29; p < 0.0001). OCT reduced GI (0.04 vs. placebo 0.00; p = 0.003) and salivary bacterial counts (2.73 vs. placebo 0.24 lgCFU/ml; p < 0.0001). Tooth discoloration was slightly higher under OCT (DI: 0.25 vs. placebo 0.00; p = 0.0011). Mild tongue staining and dysgeusia occurred. CONCLUSIONS: OCT 0.1% mouthwash inhibits plaque formation over 5 days. It therefore can be recommended when regular oral hygiene is temporarily compromised. CLINICAL RELEVANCE: When individual plaque control is compromised, rinsing with octenidine mouthwash is recommended to maintain healthy oral conditions while side effects are limited.

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A high-throughput sequencing approach was used to investigate the bacterial community diversity of traditional Tibetan yak jerky, which was collected from three different regions in Tibet and with different natural drying times. Tibetan yak jerky from different regions had different bacterial communities, which was mainly reflected in the relative abundance levels of unclassified Cyanobacteria, Psychrobacter and Acinetobacter. The unclassified Cyanobacteria was the dominant genus of Qamdo yak jerky, Acinetobacter was the dominant genus of Shigatse yak jerky, and Psychrobacteria was the dominant genus of Nyingchi yak jerky. With increasing natural drying time, the diversity of bacterial communities in yak jerky decreased, and unclassified Cyanobacteria become the dominant genus. Spearman's correlation analysis and canonical correspondence analysis revealed that physicochemical factors (moisture content, water activity, shear force and pH) were significantly correlated with bacterial community. Our results will be beneficial to improve and standardize the safety and quality of traditional Tibetan yak jerky.

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Anatomic adaptations make birds more prone to open fractures with exposed bone parts losing vascularization. As a result of this exposure, fractures are colonized by different microorganisms, including different types of bacteria, both aerobic and anaerobic, causing osteomyelitis in many cases. For this reason, antibiotic treatment is common. However, carrying out antibiotic treatment without carrying out a previous antibiogram may contribute to increased resistance against antibiotics, especially in migratory wild birds. In this paper, bacterial counts regarding fracture type, bacterial identification and antibiotic resistance have been analysed in wild birds from wildlife rehabilitation centres in Spain. The results obtained showed that open fractures had higher bacterial counts (CFU/mL) than closed ones. Bacteria in family Enterobacteriaceae, identified were Escherichia spp., Enterobacter spp., Shigella spp., Hafnia alvei, Proteus mirabilis, Leclercia adecarboxylata and Pantoea agglomerans. Other bacteria present in wild birds' fractures were Aeromonas spp., Enterococcus spp. Bacillus wiedmannii and Staphylococcus sciuri. All species found presented resistance to at least one of the antibiotics used. Wild birds can be implicated in the introduction, maintenance and global spreading of antibiotic resistant bacteria and represent an emerging public health concern. Results obtained in this paper support the idea that it is necessary to take this fact into account before antibiotic administration to wild animals, since it could increase the number of bacteria resistant to antibiotics.

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Bacteria can play different roles affecting flavors and food characteristics. Few studies have described the bacterial microbiota of butter. In the present paper, next-generation sequencing was used to determine bacterial diversity, together with aromatic characteristics, in raw cow milk butter processed by traditional fermentation, in fourteen small farms called "Malga", located in the Trentino province (Alpine region, North-East of Italy). The physicochemical and aromatic characterization of traditional mountain butter (TMB) showed a low moisture level depending on the Malga producing the butter. Counts of lactic acid bacteria, Staphylococci, and coliforms, as well as diacetyl/acetoin concentrations exhibited changes according to the geographical origin of Malga and the residual humidity of butter. MiSeq Illumina data analysis revealed that the relative abundance of Lactococcus was higher in TMB samples with the highest values of acetoin (acetoin higher than 10 mg/kg). The traditional mountain butter bacterial community was characterized by a "core dominance" of psychrotrophic genera, mainly Acinetobacter and Pseudomonas, but according to ANCOM analysis, a complex bacterial population emerged and specific bacterial genera were able to characterize the TMB bacteria community, with their high abundance, based on the Malga producing the butter.

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We initially correlated fluorescent pseudomonads and severity of enzymatic browning on fresh-cut potatoes. Subsequently, we determined the influence of inoculation with Pseudomonas fluorescens following its isolation from the brown tissues on the browning response on fresh-cut potatoes. Bacterial counts on potato slices were higher on browning tissues than on non-browning tissues. P. fluorescens that has been isolated only from the severely browning tissues developed brown discoloration on surface tissues when inoculated onto potato slices. When potato slices were initially inoculated with 103 colony-forming unit (CFU) per mL of P. fluorescens and then stored at 5ºC, bacterial counts, polyphenol oxidase (PPO) activity, phenolic content, and browning severity increased after 3 days of storage. We observed plant PPO derived from potatoes and bacterial PPO released by P. fluorescens and dictated that the plant PPO contributed to browning reactions because only the plant PPO was activated at pH 6-7 that lies in potato tissues. The PPO1 gene that contributed to browning on potatoes was expressed prominently in potato tissues following inoculation with P. fluorescens. These results indicated that P. fluorescens enhanced browning of fresh-cut potatoes by inducing the plant PPO gene, plant PPO activity, and accumulation of phenolics as a biocontrol agent.

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