Hygiene, Volume 4, Issue 2 (June 2024) – 5 articles

(1) Background: Periodontal instrumentation with dental curettes is associated with discomfort, fatigue, and musculoskeletal diseases. The goal of this study was to compare comfort, fatigue, and muscle work using three different curettes. (2) Methods: Eight hygienists each scaled three typodonts using the three different curettes. Curette A was a prototype with a novel adaptive design, Curette B had a conventional stainless-steel design, and Curette C featured a conventional silicon-covered handle. Time-based work in four muscles, comfort, fatigue, tactile feedback, grip and blade position, and pinch and grasp strength were recorded. Statistical analysis was performed using a General Linear Model (GLIM) and Tukey’s post hoc test. The level of significance was set at p < 0.05. (3) Results: Comfort, correct grasp, fingertip placement, and blade-to-tooth adaptation were significantly better with Curette A (p < 0.05). While pinch and grasp strength were significantly reduced post-instrumentation for Curettes B and C (p < 0.05), they remained unchanged for Curette A. Curette A required significantly less total muscle work and work in individual muscles, resulting in significantly less post-instrumentation fatigue than for Curettes B and C, but similar levels of tactile feedback (p < 0.05). (4) Conclusions: The ergonomic performance of a prototype adaptive periodontal curette was significantly better than that of two conventional instruments with rigid handle designs. Full article

Ralstonia spp. are low-virulent environmental Gram-negative bacteria that can cause serious nosocomial infections in immunocompromised patients. We report the characteristics of a cluster of R. insidiosa bacteremia cases occurring in our oncology day ward in Milan, Italy, between January and March 2022. A case was defined as a cancer patient attending our day ward and whose blood culture (performed because of bacteremia symptoms) led to the isolation of Ralstonia insidiosa. An epidemiological investigation was conducted in order to seek the possible source of infection. Seven adult patients received curative or palliative treatment via infusion through a Port-a-Cath (PAC). All developed symptoms within 24 h of the infusion (three during the infusion itself). Ralstonia insidiosa was isolated in the blood drawn from the PAC in all patients. All of the isolates were susceptible to carbapenems, fluoroquinolones, and piperacillin/tazobactam but resistant to aminoglycosides and cephalosporins. Systemic and/or lock antibiotic therapy led to stable symptom resolution and negative blood cultures in five patients, whereas bacteremia recurred in two patients. An epidemiological investigation suggested that extrinsic contamination of antiseptic solutions was the possible cause of the R. insidiosa infections. Although R. insidiosa is not considered a virulent pathogen, clinicians, microbiologists, and infection control teams should be aware about its potential to cause outbreaks of nosocomial bloodstream infections, especially in immunocompromised patients bearing central venous catheters. Full article

To reduce the bruising potential of machine-harvested fresh blueberries, manufacturers of over-the-row (OTR) machine harvesters are replacing the hard, plexiglass fruit-catching plates with soft, elastomeric polymers. This study assessed whether selected soft, food-grade elastomeric polymers, with the potential to be used in OTR harvesters, have a greater likelihood to encourage more microbial buildups, making cleaning/sanitation a greater challenge. Coupons of plexiglass, silicone, neoprene, and ethylene propylene diene monomer (EPDM) were exposed to fecal coliforms from various sources for biofilm development. The coupons with developed biofilms were treated with sodium hypochlorite, peracetic acid, isopropyl alcohol-based quaternary ammonium compounds (Alpet D2), or commercial dish soap. Biofilms and their residuals after the sanitizer treatments were quantified. The fecal coliforms isolated from the surface of OTR harvesters developed significantly (p ≤ 0.05) more biofilms than those from other sources. EPDM coupons had significantly more, while neoprene and silicone coupons had insignificantly different (p > 0.05) amounts of biofilms from plexiglass coupons. After sanitizer treatments, EPDM coupons had significantly more, while neoprene and certain silicon coupons had significantly fewer residues than plexiglass coupons. Study suggests that compared to plexiglass, neoprene and silicon did not support more microbial buildups or retain more biofilms after sanitizing treatments. Full article

The aim of the study was to evaluate the antimicrobial activity of the extracted plants basil (Ocimum basilicum L.), sage (Salvia officinalis L.), lavender (Lavandula officinalis L.), immortelle (Helichrysum italicum (Roth) G. Don), savory (Satureja montana L.), and rosemary (Salvia rosmarinus Spenn.) against foodborne and clinical pathogens. Dried plants were used in the production of Dalmatian cow’s milk hard cheese at concentrations of 0.5, 1.0, 1.5, and 2% to evaluate the microbiological safety and sensory properties of novel cheeses. The broadest antimicrobial activity was found in rosemary and sage, inhibiting ten indicator pathogens, and the strongest antimicrobial activity was found in immortelle and sage, which showed the widest zones of inhibition. The most sensitive indicators were Staphylococcus species and Yersinia enterocolitica. The supplemented cheeses met the official microbiological criteria and were mycotoxin negative. The surface mycobiota of control and experimental cheeses consisted mainly of Penicillium sollitum, based on the sequence analysis of the beta-tubulin and calmodulin genes. The antifungal effect of the added plants was clearly demonstrated in cheeses with added basil and sage (p < 0.05). Full article

The aim of this study was to determine the prevalence of Streptococcus (Sc.) agalactiae, Prototheca spp., Staphylococcus (S.) aureus, and especially methicillin-resistant S. aureus as well as Myco-plasmopsis (M.) spp. and M. bovis in bulk tank milk (BTM) on dairy farms in Lower Saxony, Germany. BTM samples were collected in January 2023 from 208 selected dairy farms. The samples were quantitatively culturally analyzed for S. aureus and Prototheca spp. Presumptive S. aureus colonies were further confirmed by MALDI-TOF. Presumptive Prototheca spp. colonies were confirmed by light microscopy. Sc. agalactiae and Mycoplasmopsis spp. were detected by real-time polymerase chain reaction (rtPCR). Sc. agalactiae was detected in two herds (1% (Confidence Interval 95% (CI) 0.3–3.4)). S. aureus was confirmed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) in 38 herds (18.3% (CI 13.6–24.1)), assuming a threshold of >10 cfu/mL milk. A total of 154 isolates identified as S. aureus by MALDI-TOF were transferred to agar with added oxacillin for resistance testing, of which 19 isolates (12.3% (CI 8–18.5)) showed growth. The 19 isolates came from eight different farms (3.8% (2–7.4)). Prototheca spp. were identified in 13 herds (6.3% (CI 3.7–10.4)). Mycoplasmopsis spp. were detected by PCR in 18 herds (8.7% (CI 5.5–13.3)). Of these, M. bovis was present in three herds (1.4% (0.5–4.2)). The herd prevalence of Sc. agalactiae in BTM appears to be at low levels in the sampled area. The prevalence of Mycoplasmopsis spp. in the herds was higher than expected compared to previous studies. It is interesting to note that the percentage of M. bovis in the total Mycoplasmopsis spp. was only 16.7%. Full article