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The statistical correlation between the number of oral streptococci and the results of ATP bioluminescence assay was examined and compared with the results from Streptococcus plate counts and an oral bacteria quantification system. Because a significant correlation was found between ATP (RLU) and the number of bacteria in the oral bacteria quantification system for all seven types of oral streptococci examined, ATP would reflect a conditions of oral hygiene. However, using this assay, it was observed it may be difficult to correctly evaluate bacteria that form aggregates. Furthermore, even a small number of bacteria (below 105 CFU/mL) , which cannot be measured by the oral bacteria quantification system, could be estimated by using ATP bioluminescence assay. It was suggested that this assay could be used for quantitative evaluation of the effect of oral cleaning.

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The number of live bacterial cells is the most used parameter to assess the quality of finished probiotic products. Plate counting (PC) is the standard method in industry to enumerate cells. Application of PC implies critical aspects related to the selection of optimal nutrient media and growth conditions and underestimation of viable but not cultivable (VBNC) cells. Flow-cytometry (FC) is a culture-independent methodology having the potential to selectively enumerate live, damaged, and dead cells representing a powerful tool for in-depth monitoring of probiotic products. We monitored the shelf life of a clinical batch of a synbiotic composition PDS-08 targeting the pediatric population by means of PC and FC according to International Conference on Harmonization (ICH) pharma guidelines testing the Arrhenius model as predictive tool; PC enumeration revealed higher destruction rate than FC suggesting a faster reduction in cultivability than membrane integrity and thus a possible shift of the bacteria into a VBNC status. PDS-08 maintained acidification capability over time, when re-suspended in nutrient medium, even in samples tested sub-optimally for CFU detection (below 1 billion cells/dose). Due to similar kinetics described by the study of metabolic activity and membrane integrity, FC might be suggested as a valid tool for the study of functional stability of a probiotic product.

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The risk of Procambarus clarkii eating safety attracts consumers' big concern, but it has not been addressed properly. Therefore, this study was aimed to investigate eating safety and quality of live and dead Procambarus clarkii at different stages by total volatile basic nitrogen (TVB-N), biogenic amines (BAs), total aerobic plate counts (TPC) and microbiota. The results showed that in live Procambarus clarkii, TVB-N and TPC values were below the limit despite vitality, while cadaverine in gills, intestines, and glands (GIG) exceeded in articulo-mortis Procambarus clarkii. For the dead, it showed that Procambarus clarkii posed a high risk in eating safety within one to two days after death; and BAs of high risk were putrescine and cadaverine. The dominant microorganisms threatening eating safety and quality were potentially pathogenic bacteria of Citrobacter and Acinetobacter from the environment; and spoilage bacteria of Shewanella from viscera.

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A study was conducted on 500 juvenile rainbow trout (122 ± 4 g) fed either a control diet or a treatment diet containing 300 mg/kg of a microencapsulated blend of organic acids and essential oils to elucidate effects on intestinal morphology and microbiome. Proximal intestinal villi length was significantly increased in fish fed the treatment diet. Despite no differences in gut inflammation scores, edema, lamina propria inflammation and apoptosis were completely absent in the distal intestine of fish fed the treatment diet. Next-generation sequencing of the 16S rDNA showed no differences in alpha and beta diversity, and gut bacteria were mainly composed of Firmicutes, Bacteroidetes and Proteobacteria. On the genus level, LefSe analysis of indicator OTUs showed Bacteroides, Sporosarcina, Veillonella, Aeromonas and Acinetobacter were associated with the control diet whereas Streptococcus, Fusobacterium and Escherichia were associated with the treatment diet. Aeromonas hydrophila and Acinetobacter spp. are opportunistic pathogens and several strains have been found to be resistant to antibiotics. The increase in villi length and reduction of specific pathogens indicates that feeding a microencapsulated blend of organic acids and essential oils improves gut health and may serve as a part of an effective strategy to reduce antibiotic use in aquaculture.

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Dental practices were approached to fill out a questionnaire on the infection control protocols in use to control biofilm growth in the dental unit and to send two types of water sample. Sampling of the dental units had to be performed prior to any infection control measures and on the second day of operation, to avoid residual effects of biofilm disinfection protocols performed in the weekend. Instructions were given on how to sample the units. Only samples, accompanied with a completed questionnaire and returned within two days by regular mail, were analysed. Samples were processed for heterotrophic plate counts, 16S (V4) rDNA microbiome sequencing and q-PCR for the concentration of bacterial 16S rDNA, fungal 18S rDNA, Legionella spp. and the presence of amoeba. The files contain the metadata needed to interpret and analyse the microbiome data. This dataset can be used by other scientists, members of infection control units, (trainee) bioinformaticians and policy makers. This dataset can provide leads to further unexplored parameters which could influence the microbial ecology of the dental unit.

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Sample introduction method was studied to reduce the extra-column effect in reversed-phase HPLC. Slow transport of a sample band (SToSB) in the pre-column space followed by the introduction of the band into the column at a near-optimum flow rate resulted in larger plate counts for a 1.0 mmID, 5 cm long column as much as 1.4-1.6 times for solutes with a retention factor (k) of 0.5-1.8 compared to a conventional elution method. Further reduction of the extra-column effect was possible by orthogonally splitting the sample band (SplSB) by flow switching during its slow transport followed by the introduction of the leading part of the band into the column. In this case, increased plate counts of up to 2-3 times for solutes with k of 0.5-1.8 were observed for a 1.0 mmID, 5 cm column. The sample introduction method, SToSB in the injector and the pre-column tube of a few µL, was found to reduce the extra-column band variance by 0.4-0.5 µL2 for an UHPLC system with the extra-column volume (Vextra) of ca. 4.6 µL and the system variance (σextra2) of 1.1 µL2 at flow rate of 100 µL/min, while SToSB and subsequent SplSB were found to be more effective, reducing σextra2 by about 0.8 µL2. With an UHPLC instrument with Vextra of about 10 µL and σextra2 of ca. 3.6 µL2 at flow rate of 300 µL/min, 1.4-2.1 times as many plate counts were observed with SToSB and SplSB compared to the normal elution method for early-eluting solutes with k=0.25-1.7 for a column, 2.1 mmID, 5 cm long. With this UHPLC instrument, SToSB and/or SplSB resulted in the reduction of σextra2 by 1.2-2.2 µL2.

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Bottled water as well as bottled water dispensers is widely used in the United Arab Emirates as a source of drinking water in residential, commercial, and institutional settings. The quality of such waters is of utmost concern as it has the potential to cause waterborne outbreaks, if (re)contaminated. Besides, bottled water dispensers could act as a source of contamination over time, if not cleaned properly on a regular basis. A cross-sectional study was conducted on 40 water samples collected from public and private bottled water dispensers in the emirates of Dubai and Sharjah. Samples were analyzed for heterotrophic plate count bacteria, fecal and total coliforms, and fungal growth. No total and fecal coliforms were detected in any of the samples. Heterotrophic plate counts (HPC) ranged between 0 and 100 CFU/100 ml, with an overall average of 31 CFU/100 ml. There was no significant difference between the HPC bacterial levels of public and private bottled water dispensers. However, a significant association (p < 0.05) was found between fungal growth and the location of the bottled water dispenser within the investigated sites. Survey outcomes also highlighted the need to spread awareness and knowledge amongst general public on basic cleanliness and hygiene practices contributing to safe drinking water and the need for stricter monitoring of public bottled water dispensers cleaning schedules.

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Salmonella and Campylobacter are significant issues for poultry processors because of increasing regulatory standards as well as public health concerns. The goal of this study is to report the effects of two different pre-chiller systems that utilize different temperatures and water recirculation systems on whole bird carcass rinsates. Both pre-chiller tanks were contained within a single poultry processing facility and operated at different temperatures and water systems. The incidence of Campylobacter spp. and Salmonella spp., as well as the aerobic plate counts on whole bird carcass rinses are reported in this study from each pre-chiller system. The results from this study reveal that there are significant differences in how microbial populations and pathogens change over time in each pre-chiller system. Furthermore, we identify that these patterns are different per system. Such data are impactful as it indicates that measuring carcasses within a plant must consider both temperature and water recirculation as it may prevent comparability of different lines within a single processing facility.

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BACKGROUND: Cross-contamination from inanimate surfaces can play a significant role in intensive care unit (ICU)-acquired colonization and infection. This study assessed an innovative isopropyl alcohol/organofunctional silane solution (IOS) to reduce microbial contamination on inert surfaces in a medical ICU. METHODS: Baseline adenosine triphosphate bioluminescence testing (ABT)-measurements (N = 200) were obtained on designated inert ICU surfaces followed by IOS treatment. At 1 and 6 weeks, selective surfaces were randomized to either IOS-treated or nontreated controls for comparison using ABT (N = 400) and RODAC colony counts (N = 400). An ABT value of ≤45 relative light units (RLU) was designated as "clean," whereas >45 was assessed as "dirty." RESULTS: Mean RLU baseline values ranged from 870.3 (computer keyboard) to 201.6 (bed table), and 97.5% of surfaces were assessed as "dirty." At 6 weeks, the mean RLU of surfaces treated with IOS ranged from 31.7 (physician workstation) to 51.5 (telephone handpiece), whereas values on comparative control surfaces were 717.3 and 643.7, respectively (P < .001). Some 95.5% of RODAC cultures from IOS-treated sites at 6 weeks were negative, whereas 90.5% of nontreated sites were culture-positive, yielding multiple isolates including multidrug-resistant gram-positive and gram-negative bacteria. CONCLUSIONS: IOS-treated surfaces recorded significantly lower RLU and RODAC colony counts compared with controls (P < .001). A single application of IOS resulted in a persistent antimicrobial activity on inert ICU surfaces over the 6-week study interval.

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The antimicrobial activity of a new nisin-based organic acid sanitizer (NOAS), developed in our laboratory, was tested against viable aerobic mesophilic bacteria and Salmonella populations inoculated on produce surfaces. The activity of NOAS was compared with 200 ppm of chlorinated wash water and a bioluminescence ATP technique to determine the efficacy of treatments compared with plate count methods. The activity of the 10% final concentration of NOAS against viable populations of 109 CFU/mL Salmonella in phosphate-buffered saline (PBS), sterile deionized distilled water, and buffered peptone water was tested in vitro and on grape tomatoes inoculated with Salmonella at 2.5 log CFU/g. A similar batch of inoculated tomatoes were treated with 200 ppm of total available chlorinated water. All treatments for inactivation of viable Salmonella in vitro was tested up to 30 min and 5 min for the attached populations on tomatoes. Inactivation of viable Salmonella at 109 log CFU/mL by 10% the NOAS solution averaged >107 log CFU/mL in PBS, sterile deionized distilled water, and buffered peptone water. Similarly, Salmonella bacteria inactivated on tomato surfaces by the NOAS solution was significantly (P < 0.05) greater than numbers on chlorinated washed tomatoes, and surviving bacterial populations on NOAS and chlorine-treated tomatoes were <1 and 4 CFU/g, respectively. A significant linear correlation coefficient (r2 = 0.99) between the bioluminescence ATP assay and aerobic plate counts of inoculated and untreated grape tomatoes were recorded but not with NOAS and chlorine-treated tomatoes, as bacterial populations were less than the minimum baseline for determination. Also, the results indicated that the NOAS solution is a better alternative antimicrobial wash solution than 200 ppm of chlorinated water.

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Bubble tea beverages (n = 105) purchased from vendors in Taiwan were tested to determine their microbiological and chemical quality. Nearly half of the tested samples (48.6%, 51 of 105) had aerobic plate counts (APCs) higher than the Taiwan Food and Drug Administration guideline of 4.0 log CFU/mL, and 55 (52.4%) had coliform counts (most probable number [MPN]) higher than the 10 MPN/mL guideline. Escherichia coli, Salmonella, Staphylococcus aureus, sweeteners, preservatives, maleic acid, and coumarin were not detected in any sample. However, catechins were not detected to 188 mg/mL, and caffeine was 10.1 to 457.6 mg/mL. Bubble tea samples obtained from vendors in southern Taiwan had a mean APC of 2.6 log CFU/mL and a mean coliform count of 61.7 MPN/mL; these values were significantly lower (P < 0.05) than those from samples collected from vendors in northern, eastern, or central Taiwan. Samples obtained from southern Taiwan had the highest mean catechin concentrations of 21.3 mg/mL (P < 0.05). About 60% (63 of 105) of the bubble tea samples were not labeled with the origin of the tea leaves, which is in violation of Taiwanese food labeling regulations. In general, the bubble tea beverages tested had satisfactory microbial and chemical qualities.

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Aerobic plate counts are the standard enumeration method for probiotic-containing products. This counting method is limited by the ability of many cells to enter a viable but non-culturable (VBNC) state upon exposure to stressful conditions like dehydration and heating commonly used in probiotic product preparation. Alternative enumeration methods are available including flow cytometry (FC) which counts total live/dead cells by assessing cellular integrity and/or metabolic activity, and quantitative polymerase chain reaction (qPCR) in which enumeration is correlated with the quantity of a nucleic acid target. These three methods were compared for enumerating three lactic acid bacteria (LAB): Pediococcus acidilactici, Pediococcus pentosaceus, and Lactobacillus plantarum, and a Bacillus subtilis related strain in twenty samples of a mixed probiotic product ranging in age from one to 825 days post-production. Flow cytometry and qPCR enumerations were similar and much higher compared to plate counts at later storage times, suggesting that some strains in the population were entering the VBNC state and were only countable by FC and qPCR. We propose the use of FC and/or qPCR as an alternative to plate counts for more accurate enumeration of bacteria in probiotic products.

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Infection risk management in a dental unit waterline (DUWL) involves healthcare personnel and patients and is related to routine exposure to water and aerosols that may contain bacterial species. To improve water safety plans, maintenance, and sanitation procedures, analyses of heterotrophic plate counts (HPCs) at 36 °C, and two other microorganisms frequently associated with biofilms, Pseudomonas aeruginosa and Legionella spp., were performed in order to evaluate differences in microbiological contamination between two types of DUWLs: Type A, provided by a water tank, and Type B, directly connected to municipal water. The data showed that the water supply and water safety plan differentially influenced microbiological contamination: Type A DUWLs were more contaminated than Type B DUWLs for all microbiological parameters tested, with significant changes in the percentage of positive samples and contamination levels that were beyond the limits of standard guidelines. The results obtained show how the storage tank, the absence of anti-retraction valves, and the disinfection procedures performed are the main critical points of Type A DUWLs, which confirms that dental unit management (maintenance/sanitization) is often missed or not correctly applied by stakeholders, with an underestimation of the real risk of infection for patients and operators.

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This study aimed to gain insight into the microbial quality, safety and bacterial community composition of black soldier fly larvae (Hermetia illucens) reared at different facilities on a variety of organic waste streams. For seven rearing cycles, both on laboratory-scale and in large-scale facilities at several locations, the microbiota of the larvae was studied. Also samples of the substrate used and the residue (= leftover substrate after rearing, existing of non-consumed substrate, exuviae and faeces) were investigated. Depending on the sample, it was subjected to plate counting, Illumina Miseq sequencing and/or detection of specific food pathogens. The results revealed that the substrates applied at the various locations differed substantially in microbial numbers as well as in the bacterial community composition. Furthermore, little similarity was observed between the microbiota of the substrate and that of the larvae reared on that substrate. Despite substantial differences between the microbiota of larvae reared at several locations, 48 species-level operational taxonomic units (OTUs) were shared by all larvae, among which most belonged to the phyla Firmicutes and Proteobacteria. Although the substrate is assumed to be an important source of bacteria, our results suggest that a variety of supposedly interacting factors-both abiotic and biotic-are likely to affect the microbiota in the larvae. In some larvae and/or residue samples, potential foodborne pathogens such as Salmonella and Bacillus cereus were detected, emphasising that decontamination technologies are required when the larvae are used in feed, just as for other feed ingredients, or eventually in food.

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The data presented in this article are related to the research paper titled "Prevalence of Legionella in retirement homes and group homes water distribution systems" (De Filippis, 2018) [3]. Most of the cases of Legionella infection are sporadic and occur in community-dwellers. Hot water and biofilm samples from the showerheads of 26 retirement homes and 9 group homes hosting closed communities were collected, in order to evaluate the prevalence of Legionella and generic water quality parameters (Heterotrophic Plate Counts at 22 °C and 37 °C). Samples were tested by culture method for the presence of Legionella. Confirmation and identification were carried out through Latex test and PCR. Further data about buildings' number of floors and rooms were collected, and put in relation to the presence of Legionella through constructing contingency tables and performing exact fisher׳s or Chi-square tests. Cold (< 30 °C) water samples are analyzed apart.

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This study aimed to evaluate the suitability of total aerobic plate count (APC) guidelines for raw pork (< 1 × 107 CFU/g) distributed in Korea. The APC values for raw pork collected from meat packing centers and meat shops in three provinces (Seoul/Gyeonggi, Gangwon, and Chungcheong) were reported to be ≤ 1.5 × 106 CFU/g. To evaluate practical APC guidelines for pork and meat quality, APC levels and quality traits were determined for pork under cold storage. On day 12, APC for pork was 4.3 × 106 CFU/g, which was below the guideline level, while overall acceptability scores were < 3.0, indicating that the pork was rated as not acceptable by sensory panels. Therefore, to satisfy both the microbiological safety of pork and organoleptic quality for consumer palatability, we suggest that the current APC guideline levels for pork should be lowered to 1 × 106 CFU/g.

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Extra-column band dispersion during the transport of a sample band from the injector to the column can be reduced by a flow rate program starting with a low flow rate until the sample band has approached to, or just entered into the column, followed by an increased flow rate suitable for the solute separation in the column. Such a sample introduction method increased the plate counts of a 50 mm long column, 1.0 or 2.1 mmID, especially for early-eluting solutes by up to several times compared to a conventional elution method, when a 0.254 mmID, 15.2 cm connection tubing was used. Increase in plate counts of up to 50-70% was possible for solutes with retention factors smaller than 1.0 for the columns connected with a 0.13 mmID, 15 cm tube. The method also seems to reduce the contribution of the void space at the column inlet to the band dispersion. The elution method including a slow transport of the sample band in the pre-column space of 10 µL or less may require a little longer separation time than normal elution, but it was shown to be effective for increasing the observed efficiency of a small column for solutes with small retention factors.

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Pig small intestine not only is used as food but also for sausage casings production in many countries worldwide. However, it is well recognized that the small intestine is important source of spoilage and pathogenic bacteria. The present study aimed at investigating the effects of different washing and packaging methods on the changes of microbial levels and physicochemical characteristics of pig small intestine. After collecting and trimming off of visible fats, the pig small intestine samples were treated with; (i) different packaging methods: aerobic packaging (AP), skin packaging (SP), and vacuum packaging (VP); and (ii) washing with different concentrations of acetic acid. The treated samples were then stored at 4℃ for 1, 4, 7, and 10 d. At 1-d storage, higher pH value was found in the AP-treated samples, however, after 7 to 10 days the samples treated with SP had higher values compared to the ones treated with AP and VP (p<0.05). Thiobarbituric acid reactive substances values were higher in the AP-treated samples than those of the SP- and VP- treated samples at 7-d storage (p<0.05). At 10th d, total plate counts (TPC) were higher in the control than in the acetic acid-washed samples (p<0.05). Additionally, the TPC was lower in the SP- and VP-treated samples than the AP-treated samples at 7-d storage (p<0.05). These obtained results suggest that the applications of washing with acetic acid solution and/or SP and VP methods could be an effective way to extend the shelf-life of pig small intestine during cold distribution.

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Drinking water utilities and researchers continue to rely on the century-old heterotrophic plate counts (HPC) method for routine assessment of general microbiological water quality. Bacterial cell counting with flow cytometry (FCM) is one of a number of alternative methods that challenge this status quo and provide an opportunity for improved water quality monitoring. After more than a decade of application in drinking water research, FCM methodology is optimised and established for routine application, supported by a considerable amount of data from multiple full-scale studies. Bacterial cell concentrations obtained by FCM enable quantification of the entire bacterial community instead of the minute fraction of cultivable bacteria detected with HPC (typically < 1% of all bacteria). FCM measurements are reproducible with relative standard deviations below 3% and can be available within 15 min of samples arriving in the laboratory. High throughput sample processing and complete automation are feasible and FCM analysis is arguably less expensive than HPC when measuring more than 15 water samples per day, depending on the laboratory and selected staining procedure(s). Moreover, many studies have shown FCM total (TCC) and intact (ICC) cell concentrations to be reliable and robust process variables, responsive to changes in the bacterial abundance and relevant for characterising and monitoring drinking water treatment and distribution systems. The purpose of this critical review is to initiate a constructive discussion on whether FCM could replace HPC in routine water quality monitoring. We argue that FCM provides a faster, more descriptive and more representative quantification of bacterial abundance in drinking water.

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Raw poultry are sometimes contaminated with foodborne pathogens, which can lead to illness in humans. In recent years research has focused on a variety of light technologies to decontaminate food and food contact surfaces during meat and poultry processing. In this study we evaluated the ability of 405-nm light generated from an LED array to inactivate multi-isolate cocktails of either Salmonella spp., pathogenic Escherichia coli, Staphylococcus spp., or Listeria monocytogenes suspended in chicken purge or skin. When exposed to 180 J/cm2 405-nm light at two separate light intensities (300 mW/cm2/s or 150 mW/cm2/s) the maximum pathogen reduction on chicken skin was ca. 0.4 log. When the pathogens were suspended in chicken purge the maximum log reductions ranged from 0.23 to 0.68 log (180 J/cm2; 150 mW/cm2/s) versus 0.69 to 1.01 log (180 J/cm2; 300 mW/cm2/s). Log reductions of each pathogen, when they were subjected to heat shock prior to 405-nm light treatment, were reduced, indicating that thermal effects accounted for much of the bacterial inactivation.

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