Search Results (98)

Background and Objectives: Orthodontic auxiliaries create plaque-retentive niches that may amplify biofilm accumulation and inflame adjacent soft tissues. While cross-sectional comparisons suggest higher palatal burden beneath acrylic elements, less is known about real-world patterns accumulated across years of routine care. We retrospectively evaluated periodontal and palatal outcomes, and, in a microbiology sub-sample, site-specific colonization, across three device types: molar bands, Nance buttons, and removable acrylic plates. Methods: We reviewed 2022–2025 records from a university orthodontic service, including consecutive patients aged 18–30 years with documented pre-placement and 6-month follow-up indices. Groups were bands (n = 92), Nance (n = 78), acrylic (n = 76). Standardized charted measures were abstracted: Plaque Index (PI), Gingival Index (GI), bleeding on probing (BOP%), probing depth (PD), and palatal erythema grade (0–3). A laboratory sub-sample (n = 174 visits) had archived swabs cultured for total aerobic counts (log₁₀ CFU/cm²) at the device, adjacent enamel, and palatal mucosa; Streptococcus mutans burden was available from qPCR (log₁₀ copies/mL). Results: Baseline characteristics were similar, except for longer wear at follow-up in Nance (10.1 ± 4.0 months) vs. bands (8.7 ± 3.2) and acrylic (6.9 ± 3.0; p < 0.001). At 6 months, device type was associated with greater worsening of PI and GI (both p < 0.001) and with higher palatal erythema (bands 0.7 ± 0.5; Nance 1.6 ± 0.8; acrylic 1.9 ± 0.7; p < 0.001). Microbiologically, palatal mucosal colonization was lowest with bands (3.3 ± 0.5), higher with Nance (4.9 ± 0.6), and highest with acrylic (5.0 ± 0.7; p < 0.001); S. mutans mirrored this gradient (p < 0.001). Palatal CFU correlated with erythema (ρ = 0.6, p < 0.001) and ΔGI (ρ = 0.5, p < 0.001). In adjusted models, acrylic (OR 6.7, 95% CI 3.5–12.8) and Nance (OR 4.9, 2.5–9.3) independently predicted erythema ≥2; recent prophylaxis reduced odds (OR 0.6, 0.3–0.9). Conclusions: In this single-center cohort, palate-contacting designs were associated with higher palatal biomass and erythema than bands. These associations support device-tailored hygiene considerations and proactive palatal surveillance, particularly for acrylic components. Full article

Background: Orthodontic auxiliaries can create plaque-retentive niches that inflame adjacent soft tissues. We compared bacterial colonization on molar bands, Nance buttons, and acrylic plates and assessed associated periodontal and palatal tissue responses in adolescents. Methods: In a cross-sectional study (n = 128; 10–17 years), clinical indices (Plaque Index, Gingival Index, bleeding on probing, probing depth) were recorded at device-influenced teeth. Palatal fibromucosa under palate-contacting devices was graded 0–3 (0 = none, 1 = mild/diffuse, 2 = moderate/confluent, 3 = marked with papillary hyperemia). Swabs from device surfaces, adjacent enamel, and palatal mucosa were cultured for total aerobic counts (log₁₀ CFU/cm²); Streptococcus mutans burden was quantified by qPCR (log₁₀ copies/mL). Group differences and adjusted associations were analyzed. Results: Palate-contacting devices harbored greater palatal biofilm and presented higher soft-tissue inflammation than bands. In adjusted models, device type (Nance, acrylic) remained associated with higher Gingival Index independent of measured behaviors and wear duration. Palatal colonization tracked closely with palatal erythema, supporting a local dose–response at the palatal interface. Conclusions: Appliance design is associated with distinct colonization patterns and soft-tissue responses; palate-covering acrylic components warrant device-specific hygiene and routine palatal inspection. Selecting designs with better cleansability and reinforcing plate-specific cleaning may mitigate palatal inflammation during treatment. Full article

Background/Objectives: There are many commercial mouthrinses, used for a variety of purposes, including antiseptic activity. The objective of this study was to determine the antibacterial activity of various TheraBreath™ oral rinses against the cariogenic bacterium, Streptococcus mutans, and saliva-derived microbial communities, and their antibiofilm activity against S. mutans in vitro biofilms. Methods: Bactericidal activity against planktonic S. mutans was assessed by colony counting after 30 and 2 min exposures to mouthrinses. Ten saliva samples were exposed to mouthrinses for 30 s and plated aerobically on blood agar and Mitis Salivarius agar. Mature biofilms of S. mutans were treated with mouthrinses for 15 min followed by fluorescent vitality staining and polysaccharide measurement, followed by crystal violet staining for measurement of total biofilm remaining. Statistical analysis was performed using Kruskal–Wallis with Dunn’s multiple comparisons test comparing all mean ranks (α = 0.05). Results: TheraBreath™ Fresh Breath, Healthy Smile, and Dry Mouth exhibited no significant antibacterial activity. TheraBreath™ Healthy Gums showed antibacterial activity against S. mutans and microbes from saliva samples similar to Listerine^® Naturals at all exposure times. Whitening Fresh Breath showed intermediate killing of S. mutans after 30 min in liquid but not after 2 min or against salivary microbes. Live/Dead fluorescence vitality staining showed that Healthy Gums and Whitening Fresh Breath had antibacterial activity against mature biofilms of S. mutans statistically similar to Listerine^® Naturals and Colgate^® Total; however, Whitening Fresh Breath did not have significant killing compared to PBS. Conclusions: TheraBreath™ Healthy Gums demonstrated similar antiseptic activity levels to other antiseptic-claiming commercial rinses. Whitening Fresh Breath was comparable but unable to kill in short exposure times. Full article

The demand for wild animal meat, popularly called “bushmeat”, serves as a driving force behind the emergence of infectious diseases, potentially transmitting a variety of pathogenic bacteria to humans through handling and consumption. This study investigated the microbial load and bacterial diversity in bushmeat sourced from a prominent bushmeat market in Kumasi, Ghana. Carcasses of 61 wild animals, including rodents (44), antelopes (14), and African civets (3), were sampled for microbiological analysis. These samples encompassed meat, intestines, and anal and oral swabs. The total aerobic bacteria plate count (TPC), Enterobacteriaceae count (EBC), and fungal counts were determined. Bacterial identification was conducted using MALDI-TOF biotyping. Fungal counts were the highest across all animal groups, with African civets having 11.8 ± 0.3 log₁₀ CFU/g and 11.9 ± 0.2 log₁₀ CFU/g in intestinal and meat samples, respectively. The highest total plate count (TPC) was observed in rodents, both in their intestines (10.9 ± 1.0 log₁₀ CFU/g) and meat (10.9 ± 1.9 log₁₀ CFU/g). In contrast, antelopes exhibited the lowest counts across all categories, particularly in EBC from intestinal samples (6.1 ± 1.5 log₁₀ CFU/g) and meat samples (5.6 ± 1.2 log₁₀ CFU/g). A comprehensive analysis yielded 524 bacterial isolates belonging to 20 genera, with Escherichia coli (18.1%) and Klebsiella spp. (15.5%) representing the most prevalent species. Notably, the detection of substantial microbial contamination in bushmeat underscores the imperative for a holistic One Health approach to enhance product quality and mitigate risks associated with its handling and consumption. Full article

Antimicrobial use in food animals selects for antimicrobial-resistant (AMR) bacteria, which most commonly reach humans via the food chain. However, AMR bacteria can also escape the feedyard via agricultural runoff, manure used as crop fertilizer, and even dust. A study published in 2015 reported AMR genes in dust from cattle feedyards; however, one of the study’s major limitations was the failure to investigate gene presence in viable bacteria, or more importantly, viable bacteria of importance to human health. Our main objective was to investigate the presence and quantity of viable bacteria and antimicrobial-resistant (AMR) determinants in fugitive bioaerosols from cattle feedyards in the downwind environment. Six bioaerosol sampling campaigns were conducted at three commercial beef cattle feedyards to assess variability in viable bacteria and AMR determinants associated with geographic location, meteorological conditions, and season. Dust samples were collected using four different sampling methods, and spiral plated in triplicate on both non-selective and antibiotic-selective media. Colonies of total aerobic bacteria, Enterococcus spp., Salmonella enterica, and Escherichia coli were enumerated. Viable bacteria, including AMR bacteria, were identified in dust from cattle feedyards. Bacteria and antimicrobial resistance genes (ARGs via qPCR) were mainly found in downwind samples. Total suspended particles (TSPs) and impinger samples yielded the highest bacterial counts. Genes encoding beta-lactam resistance (bla_CMY-2 and bla_CTX-M) were detected while the most common ARG was tet(M). The predominant Salmonella serovar identified was Lubbock. Further research is needed to assess how far viable AMR bacteria can travel in the ambient environment downwind from cattle feedyards, to model potential public health risks. Full article

Traditional methods of microbial quantification of irrigation water using colony counts from agar culture require dedicated laboratory space and trained personnel, limiting their on-site applicability. Dehydrated Petrifilm™ plates are a simpler alternative but still require 2–3 days to culture. Adenosine triphosphate (ATP) tests may offer a fast and reliable method for quantifying microbes in water. In this study, we compared (a) microbial quantification based on ATP assays with Petrifilm™-based assays, and (b) we evaluated the effectiveness of cold plasma or ozone treatments in controlling microbial growth at various oxidation–reduction potential (ORP) levels. Lake water was recirculated through an ozone or cold plasma treatment system until a target ORP of 700 mV was reached. Samples were collected at various ORP levels and plated for aerobic bacteria and yeast and mold counts using Petrifilm™ plates. The free and total ATP concentrations were measured using the Hygiena EnSURE luminometer and its accompanying free and total ATP swabs. Microbial ATP was calculated by subtracting the free from the total ATP. Cold plasma and ozone showed similar effects on microbial inactivation at 700 mV (p < 0.05). Both treatments achieved complete fungal inactivation at 600–700 mV ORP, bacterial inactivation at 600 mV ORP, and near-complete inactivation of microbial ATP at 600–700 mV. A moderate positive correlation (Pearson’s correlation = 0.39 and Spearman’s rank correlation = 0.39) was observed between the Petrifilm™ bacterial counts and microbial ATP levels, suggesting ATP quantification could complement Petrifilm™ for rapid and non-selective onsite microbial assessment of irrigation water. Full article

This study explores the use of silver nanoparticles (Ag NPs) and zinc oxide nanoparticles (ZnO NPs), either singly or in combination, for the nanoremediation of aquaculture wastewater. Aquaculture wastewater was treated with varying doses of Ag NPs and ZnO NPs across the following six groups: Group 1 (0.05 mg Ag NPs/L), Group 2 (1 mg ZnO NPs/L), Group 3 (0.05 mg Ag NPs/L + 1 mg ZnO NPs/L), Group 4 (0.025 Ag NPs/L + 0.5 mg ZnO NPs/L), Group 5 (0.1 mg Ag NPs/L + 2 mg ZnO NPs/L), and a control group. Water quality, microbial loads and nanomaterial concentrations were assessed over ten days. Transmission electron microscopy (TEM) showed average particle sizes of 102.5 nm for Ag NPs and 110.27 nm for ZnO NPs. The removal efficiencies of NH₄-N were over 98% across treatment groups. In addition, COD removal efficiencies were 33.33%, 68.82%, 49.59%, 61.49%, and 37.65%. The log-reductions in aerobic plate counts for the nanoparticle-treated wastewater were 1.191, 1.947, 1.133, 1.071, and 0.087, compared to a reduction of 0.911 in untreated wastewater. Silver concentrations ranged from 0.0079 to 0.0192 mg/L, while zinc concentrations ranged from 0.3040 to 0.9740 mg/L, indicating that ZnO-NPs represent a sustainable treatment method for aquaculture wastewater. Full article

Background/Objectives: Non-replicating persisters (NRPs) of Mycobacterium abscessus are a bacterial subpopulation that can survive in the host under unfavorable conditions, such as hypoxia or nutrient starvation. The eradication of these bacteria is difficult, which is one reason for the long treatment duration and treatment failure. The drug discovery process should therefore contain methods to screen activity against NRPs. Methods: A hypoxic environment is used to generate NRPs of M. abscessus that are termed low-oxygen persisters (LOPs). For this, an oxidation process is used to transition a replicating culture of M. abscessus distributed in microtiter plates within a sealable box into LOPs. Colony counting, automated object counting, bactericidal activity determination of known agents, and confocal laser scanning microscopy are used to study the obtained culture. Results: The obtained culture shows typical attributes of non-replicating cells, such as significantly reduced replication, the reversibility of the LOP state under aerobic conditions, delayed regrowth on solid medium, altered morphological patterns on a single-cell level, and phenotypical resistance against a variety of clinically relevant antimycobacterial compounds. The study reveals metronidazole and niclosamide as bactericidal against M. abscessus LOPs. These compounds can be used as LOP verification compounds within the described model. Conclusions: Our model is easily implemented and quickly identifies compounds that are inactive under hypoxic conditions. It can therefore accelerate the identification of clinically effective antimycobacterial drug substances, and can be a helpful tool during the drug development process. Full article

Globally, poultry products have been associated with outbreaks of foodborne illnesses. The aim of this study was to evaluate the effects of cold storage period, carcass weight, and product form on fresh broiler bacteriology and meat quality parameters. A total of 500 one-day-old broiler birds were raised to market age (28–35 days) before slaughtering. The carcasses were classified into two groups: light weight (approximately 1100 ± 50 g) and heavy weight (approximately 1400 ± 50 g). After 4 h of post-chilling aging, 256 carcasses were randomly selected to represent the two categories. Each category of 128 carcasses was randomly distributed into two groups of 64 carcasses. One group was stored as whole carcasses, while the other group was stored as part-cut deboned breast meat at 4 °C for 1, 3, 5, and 7 days of cold storage (16 samples per storage day). Post-chilling temperature, pH, cooking loss, water holding capacity, and shear force were significantly affected by product form and storage period. Water holding capacity and shear force were also affected by carcass weight (p < 0.001). Meat colors (L*, a*, b*, chroma, and hue values) were significantly affected by the storage period. The L* value was only affected by product form and carcass weight (p < 0.01). Crude protein and ether extract were significantly affected by carcass weight and storage period, while ash was only affected by carcass weight. Aerobic plate count, psychrotrophic count, proteolytic count, lipolytic count, and coliform count were significantly increased with storage time. In conclusion, carcass weight had no impact on overall meat quality, but the meat began to deteriorate and showed an increased spoilage rate after five days of cold storage. Full article

In order to obtain high-performing yeast strains from ruminants, it is necessary to select them from species such as beef cattle, dairy cows, goats, and buffalo. A total of 91 isolated yeasts were collected using the standard methods of microbial culture on agar medium followed by streaking on a plate at least three times until pure yeast colonies were formed. The API 20C AUX Kit and sequencing of the D1/D2 domain of the 26S rRNA gene were used to identify the genera Candida spp., namely, C. glabrata (99% identification), C. tropicallis (99%), C. rugosa (98%), and Issatchenkia orientalis (99%). A total of 12 yeast strains (Dc4, 14, 18; Be1, 2, 7; Bu3, 4, 7; and Go10, 16, 19) were chosen for further analyses. The performance criteria included the ability to tolerate pH values between 3.5 and 7.5, total volatile fatty acids (TVFAs, 0, 0.25, 0.5, 1, 2, and 4% of broth medium), anaerobic growth rate, and in vitro gas production efficiency. First, when all strains were grown at pH values between 3.5 and 7.5, Bu3 and Dc18 performed better than the other strains. Second, at a ruminal pH of 6.5 and a TVFA concentration of between 2 and 4% of the broth medium, strain Bu3 was more resistant than the other strains. Under anaerobic conditions, all strains experienced a decline in viable cell counts when compared with those under aerobic conditions. However, compared to strains Dc14, Be1, Be2, Be7, and Bu3, strain Dc18 exhibited more viable cells under anaerobic conditions in broth medium. The response of strain Dc18 did not differ from those of strains Dc4, Bu4, Bu7, or G16. Strains Be7, Bu3, and Dc18 were used for an in vitro fermentation experiment involving incubation for 2, 4, 6, 8, 10, 12, 24, 36, 48, and 72 h. Three ruminal cannulated dairy cows were used as donors of ruminal fluid. The treatments were run in triplicate. The addition of yeast culture had no effect on gas kinetics, gas accumulation, or the ratio of acetic acid and propionic acid, but led to significantly greater butyric acid concentrations at 24 h of incubation. In conclusion, strain Dc18 isolated from dairy cows is suitable for future studies of probiotic yeast development. Full article

Background: Food insecurity is a major global problem, with over 2.8 billion people reported as unable to afford a healthy diet in 2022. While charitable food assistance programs (CFAPs) play an important role in improving food access, ensuring the quality and safety of donated foods is crucial for safeguarding needy communities from food-related illnesses. This study evaluated the safety and quality of food donations at a food bank warehouse in the eThekwini District using a novel methodology. Methods: In March 2024, a five-day audit was conducted at a food bank warehouse in the eThekwini District, KwaZulu-Natal, South Africa. A mobile device was utilized to document comprehensive information on all incoming deliveries, including the type of food, product details (such as brand, name, and variety), donor information, weight, and date markings. The audit assessed 1037 items, totaling 64,818 kg of donated food, against established food safety standards. Each item was visually inspected upon arrival and classified as ‘unsuitable’, ‘potentially unsafe’, or ‘unsafe’ for human consumption. Results: Out of the 64,818 kg of donated food, 95.5% (61,886 kg) was deemed satisfactory. However, 4.5% of the total, which amounts to 2932 kg, was categorized as either unsafe (355 kg), potentially unsafe (1182 kg), or unsuitable (1395 kg) for consumption. Retail supermarkets donated the largest weight of food, and also of the food classified as unsafe or unsuitable. Conclusions: The study highlights an urgent need for improved quality control and safety measures in food donations to CFAPs. Stricter handling and inspection guidelines are essential to ensure the quality of charitable food, reduce health risks, and build public trust in donation programs. Full article

To understand better the high microbial load in dried laver (Porphyra yezoensis or nori), this study analyzed the aerobic plate count (APC), coliform count, temperature change, and microbiota of processing water, laver materials, and food contact surface (FCS) samples from three processing plants during the dried laver processing season from December 2023 to April 2024. The seawater used for the first washing had a low microbial load (APCs < 1–2.85 log CFU/g; coliform < 1 log CFU/g) and was dominated by Proteobacteria, Firmicutes, and Bacteroidota. The microbial load of fresh laver (4.21–4.76 log CFU/g) remained unchanged after seawater washing, but significantly increased after continuous shredding, sponge dehydration, first drying, and with the seasonal temperature rise. The microbiota of laver before drying was vulnerable between processing steps and seasons, but consistently shifted back to fresh laver microflora and was dominated by Flavobacteriaceae after drying. The FCSs (except for the curtain), which had a high microbial load (APCs 5.25–8.26 log CFU/g; coliform 1.52–4.84 log CFU/g) with similar microbiota to seawater, caused the secondary contamination of laver during processing. This study revealed the microbial proliferation of laver and seawater microflora in the continuous processing line with high nutrients and with the seasonal processing water temperature rise caused by the local weather, highlighting the need for routine cleaning and sanitizing, better washing of fresh laver, and low temperature control for future dried laver production. Full article

Contamination of fresh blueberries via contact with an equipment surface is an important food hygiene/safety issue. In this study, four and six over-the-row blueberry machine harvesters in Georgia or Oregon were each sampled twice on two different harvest days in the 2022 harvest season. Nine sites on the top loaders (n = 8) and seven sites on the bottom loaders (n = 2) were sampled before and after cleaning/sanitation. Populations of total aerobes (TA), total yeasts and molds (YM), total coliforms (TC), and the presence of fecal coliforms (FC) and enterococci (EC) in collected samples were determined. Data collected was analyzed using the split-plot ANOVA of SAS. On average, cleaned/sanitized surfaces had about one log lower (p ≤ 0.05) TA and YM counts than the uncleaned surfaces, while no difference in TC counts was observed. The vertical and horizontal conveyors and fruit-catch plates had significantly higher TA, YM, and TC counts than other sampled sites. FC and EC were detected in 7.8% or 14.1% of the Georgia samples and 5.6% or 10.2% of the Oregon samples. The type and concentration of sanitizers and frequency and approach of cleaning/sanitation treatments all impacted the hygiene status of berry-contact surfaces of machine harvesters. Full article

Cassava is an important staple food that contributes to the food security of small-scale Mozambican farmers. In southern Mozambique, cassava roots are usually processed into cassava roasted flour, locally known as “rale”. The handling and processing practices connected to “rale” production may introduce microbial contamination. We assessed the microbial contamination of “rale” processed in local farmers’ associations and consumed either locally or sold in rural markets. Microbial sampling was carried out both during the warmer rainy and cooler dry seasons, and microorganisms of relevance for food safety and fermentation were enumerated. The results revealed variation in terms of microbial diversity in all stages of cassava root processing. In samples collected in the warmer rainy season, molds, lactic acid bacteria, general aerobic bacteria and Bacillus spp. were isolated, whereas in samples collected in the cooler dry season, other groups of microorganisms such as yeasts and Staphylococcus aureus were present. Wickerhamomyces anomalus, Rhodotorula mucilaginosa, Pichia exigua, Meyerozyma caribbica and Torulaspora delbrueckii were the most frequent yeast species found within the cassava processing stages. Aflatoxin-producing molds were observed infrequently in this study, and only at low counts, thus, the risk for aflatoxin contamination appears to be low. The results obtained from the Illumina 16S rRNA gene sequencing can be considered a complementary technique to the plating methods relied on in this study. From a food quality and safety point of view, this staple food does not appear to pose a high risk for foodborne disease. Full article

Determining the microbial quality and safety of meat is crucial because of its high potential to harbor pathogens. To address the critical knowledge gap and shed light on potential contamination risk in the meat supply chain, this study aimed to assess the underexplored microbial quality and safety of marketed beef meat in Oman. Thirty-three beef meat samples from six hypermarkets were analyzed for Aerobic Plate Count (APC), Psychrotrophic Bacteria Count (PBC), and coliform and Escherichia coli counts. Prevalences were 93% and 94% (means: 2.8 ± 1.1 and 2.6 ± 0.8 log CFU/g, respectively) for coliform, and 80% and 83% (means: 1.8 ± 1.4 and 1.7 ± 0.9 log CFU/g, respectively) for E. coli in imported and local samples, respectively. The mean counts of APC (6.3 ± 0.1 log CFU/g) and PBC (6.2 ± 0.2 log CFU/g) were statistically similar but different from those of coliform and E. coli. Bacterial identification using VITEK 2 compact revealed spoilage bacteria (Pseudomonas luteola, Pseudomonas fluorescens, and Shewanella putrefaciens) and pathogenic bacteria (Acinetobacter bumannii complex, Aerococcus viridans, Enterococcus faecalis, and Oligella ureolytica), which demonstrates a potential for both spoilage and pathogen-related risks. It is concluded that the APC counts of all samples exceeded acceptable standards set by the G.C.C. Standardization Organization (GSO), which was established to protect food safety and public health in Oman and other Gulf countries. This suggests an increased risk of spoilage and pathogen contamination. This study provides one of the earliest reports of microbial contamination levels in meat, serving as an eye-opener for policymakers and stakeholders. It highlights a need for stricter hygiene protocols and improved meat handling and processing practices to enhance meat safety and protect public health in Oman and the Gulf region. Full article