Microbial Surface Contamination Research Articles

Comparative performance of contact plate metod and swab method for surface microbial contamination on medical fabrics

BackgroundThe contact plate method is widely accepted and used in various fields where hygiene and contamination levels are crucial. Evidence regarding the applicability of the contact plate method for sampling fabric microbial contamination levels in real medical environments was limited. This study aimed to assess the applicability of the contact plate method for detecting microbial contamination on medical fabrics in a real healthcare environment, thereby providing a benchmark for fabric microbial sampling methods.MethodsIn a level three obstetrics ward of a hospital, twenty-four privacy curtains adjacent to patient beds were selected for this study. The contact plate and swab method were used to collect microbial samples from the privacy curtains on the 1st, 7th, 14th, and 28th days after they were hung. The total colony count on each privacy curtain surface was calculated, and microbial identification was performed.ResultsAfter excluding the effects of time, room type, and curtain location on the detected microbial load, the linear mixed-effects model analysis showed that contact plate method yielded lower colony counts compared to swab method (P < 0.001). However, the contact plate method isolated more microbial species than swab method (P < 0.001). 291 pathogenic strains were isolated using the contact plate method and 133 pathogenic strains were isolated via the swab method. There was no difference between the two sampling methods in the detection of gram-negative bacteria (P = 0.089). Furthermore, the microbial load on curtains in double-occupancy rooms was lower than those in triple-occupancy rooms (P = 0.021), and the microbial load on curtains near windows was lower than that near doors (P = 0.004).ConclusionContact plate method is superior to swab method in strain isolation. Swab method is more suitable for evaluating the bacterial contamination of fabrics.

Enhancing Surgical Safety: Microbiological Air Control in Operating Theatres at University Medical Centre Maribor.

the aim of the study was to assess microbiological air quality in operating theatres by determining the level of microbiological contamination of the air and critical surfaces using the passive air sampling method and compliance of the operating theatre staff with infection control measures. The prospective study was conducted in the surgical block of the University Medical Centre Maribor. For two months continuously, ten operating theatres were assessed for microbial contamination of air and surfaces during quiet and active times of the day. A passive air sampling method with Petri dishes on an agar specially adapted for this purpose (plate count agar) was used. In addition, ten surgical procedures were observed to assess staff compliance with recommended practises. Air samples met microbiological standards in all operating theatres. In both sampling sessions of the day (quiet and active periods), microbial contamination of the air was always within the limit of 10 CFU/m3. The average number of bacterial colonies was zero to two during quiet phases and one to four during active phases. Approximately 60% of the isolates from the operating theatres belonged mainly to the genus Staphylococcus: S. epidermidis (36% of the isolates), S. hominis (17.5%) and S. haemolyticus (5.5%). The rest were identified as Streptococcus anginosus (23%) and Bacillus sp. (18%). Pathogenic bacteria and moulds were not present. In regard to staff compliance with good surgical practise, the former varied by behaviour and function, with non-compliance in pre-operative skin preparation and operating theatre congestion being notable. The cleanliness of the environment was satisfactory. Microbiological air control is extremely important for the safety and success of both surgical and postoperative practises. In spite of good results obtained in the study, further improvements in surgical staff compliance with good surgical practise are essential to reduce surgical site infections.

On-chip bioluminescence biosensor for the detection of microbial surface contamination

Detection of microbial pathogens is important for food safety reasons, and for monitoring sanitation in laboratory environments and health care settings. Traditional detection methods such as culture-based and nucleic acid-based methods are time-consuming, laborious, and require expensive laboratory equipment. Recently, ATP-based bioluminescence methods were developed to assess surface contamination, with commercial products available. In this study, we introduce a biosensor based on a CMOS image sensor for ATP-mediated chemiluminescence detection. The original lens and IR filter were removed from the CMOS sensor revealing a 12 MP periodic microlens/pixel array on an area of 6.5 mm × 3.6 mm. UltraSnap swabs are used to collect samples from solid surfaces including personal electronic devices, and office and laboratory equipment. Samples mixed with chemiluminescence reagents were placed directly on the surface of the image sensor. Close proximity of the sample to the photodiode array leads to high photon collection efficiency. The population of microorganisms can be assessed and quantified by analyzing the intensity of measured chemiluminescence. We report a linear range and limit of detection for measuring ATP in UltraSnap buffer of 10–1000 nM and 225 fmol, respectively. The performance of the CMOS-based device was compared to a commercial luminometer, and a high correlation with a Pearson's correlation coefficient of 0.98589 was obtained. The Bland-Altman plot showed no significant bias between the results of the two methods. Finally, microbial contamination of different surfaces was analyzed with both methods, and the CMOS biosensor exhibited the same trend as the commercial luminometer.

Understanding the significance of microbiota recovered from health care surfaces

Microbial contamination of hospital surfaces remains despite adherence to routine disinfection. Our study demonstrates bioburden from various types of hospital high-touch surfaces and the pathogenicity of all bacteria recovered. Several high-touch hospital surfaces from a single medical-surgical unit were sampled and cultured using replicate organism detection and counting (RODAC) Tryptic Soy agar plates. Colonies were then subcultured to blood agar plates and speciated using MALDI-TOF. The local microbiology laboratory database was queried for any clinical isolate match with the environmental samples recovered. Manikins, bed rails, and workstations-on-wheels were the most contaminated surfaces with the largest variety of bacteria isolated from manikins and bed rails. A total of 60 different types of pathogens were isolated, 18 of which were well-known pathogens, and 7 were classified as important in the health care setting by CDC. Our clinical microbiology laboratory identified 29 of 60 hospital surface bacteria in clinical isolates. Urine, soft tissue, and blood were the most common sources of clinical isolates. Surfaces in the health care environment harbor both well-known and not-so-well-known human pathogens. Several not-so-well-known pathogens are skin flora or environmental bacteria, which in the right setting, can become pathogenic and cause diseases including meningitis, brain abscess, endocarditis, and bacteremia.

“Graphene nanospikes exert bactericidal effect through mechanical damage and oxidative stress”

Microbial contamination of biomedical surfaces is an important clinical challenge, driving the development of new antibacterial materials. Nanoprotrusions on the wing surface of some insects have intrinsic antibacterial and antifouling properties, which inspires fabrication of biomimetic nanopatterns on medical devices. Herein, we report a broad-spectrum bactericidal surface consisting of graphene nanospikes synthesized by plasma-enhanced chemical vapor deposition. Similar coatings have been reported before, but the killing mechanism and main parameters for efficiency of such coatings have not been clarified. We investigated the correlation of anti-biofilm efficiency of graphene nanospikes to their major physicochemical parameters. While height and thickness of nanospikes did not directly correlate with bactericidal effects, edge/defect density showed linear correlation with lethality for both Gram-negative and Gram-positive bacteria. We further demonstrated that the killing mechanism is synergistic, depending on physical rupture of bacterial membranes as well as considerable oxidative damage to the cells. Of note, for the first time, we quantify the level of oxidative stress induced by graphene nanospikes in two bacterial species using genetically encoded biosensors. Our work provides a fundamental understanding of the impact of various parameters of graphene nanostructures on the bactericidal efficiency, enabling rational design of graphene-based bactericidal surfaces.

Metagenomic insights into microbial contamination in critical healthcare environments and the efficacy of a novel "HLE" disinfectant.

Bacterial contamination on inanimate clinical surfaces is directly linked to severe health problems, especially those caused by multidrug resistant (MDR) pathogens. Here, we evaluated the microbial burden in these environments and tested the efficacy of a novel HLE disinfectant solution. Microbial contamination of healthcare surfaces [Intensive Care Unit (ICU), Long Period Hospitalization Room (LPHR) and Otolaryngology Consultation (OC)] and the efficacy of HLE disinfectant solution were determined analyzing the viable counts on general and selective media, and also by molecular studies focused on metagenomic and specific qPCR. Different contamination loads were detected with LPHR showing the highest contamination. Treatment with the HLE disinfectant solution curbed the spread of well-adapted pathogens on touched surfaces (ICU, LPHR and OC). Metagenomic analysis of microbial diversity of the Patient Table (most contaminated surface in LPHR) revealed the presence of mainly A. johnsonii and P. putida. Furthermore, functional annotation of toxin, virulence and antibiotic resistance sequences showed a high diversity of Acinetobacter spp. and Pseudomonas spp. In this context, specific qPCR analysis confirmed the efficacy of HLE disinfectant solution against the most prevalent and critical pathogens Pseudomonas sp. and Acinetobacter sp. achieving their complete eradication. Given the persistence of detrimental resistant pathogens, the application of HLE disinfection solution could be a highly beneficial and effective option -used either alone or in combination-for infection prevention and control with the aim to eliminate microbial pathogens and their genes from contaminated contact-surfaces and thus limit the spread to humans and other ecological niches.

The Antibacterial Effect of the Films Coated with the Layers Based on Uncaria tomentosa and Formitopsis betulina Extracts and ZnO Nanoparticles and Their Influence on the Secondary Shelf-Life of Sliced Cooked Ham

Microbial surface contamination of the cooked ham sliced by shop assistants has an influence on its potential secondary shelf-life. Active packaging may be the solution. The first goal of the work was to obtain coatings based on Formitopsis betulina and Uncaria tomentosa extracts (separately), with the addition of nanoparticles of ZnO (as a synergetic agent to increase plant extracts’ antimicrobial effectiveness), that could be active against selected bacterial strains. Another aim of the work was to determine the influence of obtained active layers on microbial purity and texture of the samples. The results of the study demonstrated that the layers containing F. betulina or U. tomentosa extracts with the addition of ZnO nanoparticles inhibited Staphylococcus aureus, Bacillus atrophaeus, and Escherichia coli growth completely and decreased the number of Pseudomonas syringae cells. Analyzing microbial purity of sliced cooked ham portions after storage, it was observed that the active packaging based on U. tomentosa extracts had a greater influence on the total count than the coatings containing F. betulina extracts and that both active packaging materials affected the microbial purity of the cooked ham. Analyzing the textural parameter changes after 48 h of storage, a decrease in the gumminess, chewiness and cohesiveness values was noted, but only for the ham portions stored in bags covered with the coating based on U. tomentosa. The effectiveness of the active packaging on textural parameters after 96 h of storage was not noticed.

Bacteriological quality assessment of poultry chicken meat and meat contact surfaces for the presence of targeted bacteria and determination of antibiotic resistance of Salmonella spp. in Pakistan

During the slaughtering process, the meat product cross-contaminates with the surrounding contact surfaces. This study aimed to assess the level of microbial contamination of poultry chicken meat and contact surfaces at poultry slaughterhouses in the Hyderabad and Jamshoro districts of Pakistan. A total of 38 slaughter shops were selected, and from each shop, three types of samples were collected. All the samples were assessed for the presence of three microbes, Salmonella, Shigella, and E. coli by using some culture-based techniques, and for Salmonella, antibiotic resistance was also determined. Results revealed that Shigella was present in 86.8% of knives, 94.7% of chopping board and 97.3% of meat samples. While, the E. coli was present in 86.8% of knife, 97.3% of chopping board, and 97.3% of meat samples. Salmonella was detected in 97.3% of knives, 92% of chopping boards, and 97.3% of meat samples. All the isolates of Salmonella exhibited resistance to one or more antibiotics. Resistance to ampicillin, gentamicin, cefotaxime, erythromycin, neomycin, streptomycin, and sulphamethoxazole were evident in 91.7%, 25.6%, 32.1%, 40.3%, 33.9%, 34.8%, and 52.2% respectively. However, only 6.4% of isolates showed resistance to azithromycin (6.4%), and none of them showed resistance to ceftazidime. Moreover, 61.4% (67/109) of isolates were multiple drug-resistance (MDR). A high prevalence of Salmonella, Shigella, and E. coli in meat and on contact surfaces can be considered a major risk for human health. It is vital to continue developing strategies to limit the danger of foodborne diseases in slaughtering facilities.

Effectiveness of sanitation regime in a milking parlour to control microbial contamination of teats and surfaces teat cups'.

The major sources of bacterial contamination of raw milk are post-harvest manipulation; therefore the disinfection of teat and teat cups which decrease the bacterial load has a positive impact on minimizing new infection rates. The aim of the study was determination of the incidence of pathogens on investigated surfaces, evaluation of the effectiveness of sanitation regime in the reduction of surface microbial load, and determination of the effectiveness of mechanical cleaning of teats in a milking parlour for dairy cows. Samples from surfaces were taken by microbiological swabs using a sterile cotton swab from area of 5×2cm2. Sanitation regime was evaluated based on the effectiveness of active substances - lactic acid and sodium hypochlorite. From a total of 105 swab, 44 samples were found positive for Staphylococcus aureus, 16 samples for E. coli, 15 samples for Micrococcus spp., 8 samples for Staphylococcus xylosus, 9 samples for Staphylococcus cohni urealyticum, 1 sample for Enterococcus faecalis. Among isolates, S. aureus was the predominat species from teats - 19/45, teat cups, 15/45 and from wiping cloths 10/15. Sanitation regime was confirmed by a decrease in the number of coliform bacteria (CB) determined on teat and teat cups from 2.33-0.95 Log10 CFU/cm2 (p<0.001) and 0.90-0.62 Log10 CFU/cm2 (p<0.001), respectively, and in the number of total bacteria count (TBC) determined on teat and teat cups from 4.36-0.99 Log10CFU/cm2 (p<0.001), and 1.85-0.77 Log10 CFU/cm2 (p<0.001), respectively. Incidence of CB (2.53 Log10 CFU/cm2) and TBC (3.83 Log10 CFU/cm2) on wiping cloths after mechanical cleaning of udders stress the importance of this step. Results show that disinfectant with lactic acid as the main active ingredient is suitable for bacterial reduction. Post-milking disinfection of teat and teat cups reduces bacterial contamination and proves to be most effective against environmental bacteria.

Surface Microbial Contamination and Air Quality before and after Regular Cleaning Procedures

Studies on indoor air quality (IAQ) have linked exposure to microorganisms in indoor air to a variety of illnesses. The association between indoor air quality, surface contamination, and IAQ under heterogeneous cleaning procedures are all crucial factors that were investigated in this study. The ATP bioluminescence test demonstrated a significant correlation (r = 0.89; p 0.05) with bacterial count obtained from swab specimens and a moderate correlation (r = 0.57; p 0.001) with viable settling bacterial count. For the entire sample (pre- and post-cleaning), the ATP values were heterogeneous, averaging 230 RLU/100 cm2, 140 RLU/100 cm2, 120 RLU/100 cm2, 135 RLU/100 cm2, 99 RLU/100 cm2, and 80 RLU/100 cm2, in offices, classrooms, toilet doorknobs, reception desks, main lobbies, and exit doorknobs, respectively. An insignificant association between indoor and outdoor PM2.5 (r = 0.21; p 0.05), an I/O ratio of PM2.5 with an average value of 1.2, and an I/O ratio of CO2 exceeding 1 suggest a minor impact of outdoor air. After cleaning, the bacterial and fungal counts on indoor surfaces showed significant reduction, suggesting that the cleaning procedures were effective. The concentrations of VOC but not HCHO in indoor air were significantly affected by cleaning, but not by temperature or relative humidity (RH). We propose ATP bioluminescence as a surrogate for detecting bacterial contamination rather than fungal contamination, which requires additional validation. We suggest that the results of active microbial sampling (in CFU/m3) and settling plates (in CFU/m2/h) be interpreted independently to avoid confusion.

Influence of germicidal ultraviolet radiation UV-C on the quality of Apiaceae spices seeds

BackgroundSpices are susceptible to surface microbial contamination. Countries’ ban on ethylene oxide fumigation due to possible residual toxicity encouraged the usage of irradiation. Surface sterilization with low doses of ultraviolet radiation has been extensively researched as a safe, eco-friendly, and fast route. This study examines the quality of Apiaceae spices for consumption, including anise, fennel, caraway, and cumin, in response to germicidal ultraviolet radiation using a developed sterilization unit.MethodsThe influence of UV-C (254 nm, 10.5 mW/cm2) on the fungal and microbial count, germination percentage, respiration rate, phenolic content, essential oil, and the activity of antioxidant enzymes was investigated at exposure durations of 0–45 min in increments of 5 min. The treated seeds were packed in polyethylene bags in a naturally aerated storage room for 30 days before the inspection.ResultsThe obtained data showed that UV-C stimulated seeds germination and increased respiration rate for all studied types. The 25 min of exposure exhibited the highest significant values compared to the control, considered a good indicator of seed vigor. In addition, UV-C exposure between 20 and 35 min promoted the accumulation of phenolic compounds and increased the oil content as a defense mechanism against radiation. Conversely, higher exposure to UV-C led to a significant reduction in phenolic and oil contents. Furthermore, the exposure to UV-C radiation enhanced the activity of antioxidant enzymes in terms of peroxidase and catalase, which progressively increased with increasing exposure durations, reached their peak at 25–30 min, and subsequently declined with extended exposure time was extended. In a similar pattern, exposure to UV-C radiation increased polyphenol oxidase activity to its highest level at 25 min, owing to the development of antioxidant protective mechanisms against oxidative stress.ConclusionUV-C irradiation in the range of 25–30 min is the most appropriate pretreatment to maintain the vitality of the examined seeds.Graphical

Evaluation of baseline cleanliness of food contact surfaces in Basrah Governorate restaurants using ATP-bioluminescence to assess the effectiveness of HACCP application in Iraq

The Hazard Analysis and Critical Control Points (HACCP) system prevents and manages physical, chemical and biological risks at places where foods and beverages are processed, packaged, distributed and consumed. The present study (1) assessed the level of microbial contamination of food contact surfaces using adenosine triphosphate (ATP)-bioluminescence in Iraq restaurants; (2) investigated the level of microbial contamination of food contact surfaces; and (3) evaluated the efficiency of sanitizers in removing biological hazards from food contact surfaces. The ATP-bioluminescence discovered the presence of Escherichia coli and Staphylococcus aureus on surfaces and tools. Results also showed that the HACCP application was very effective in the amelioration of food quality.

IMPACT OF GALVANIZATION ON THE COURSE OF THE WOUND PROCESS IN THERMAL BURNS

Resume. The aim of the research was to study the feasibility of galvanization in the case of superficial and deep dermal thermal burns.&#x0D; Materials and methods. The efficiency of the direct current electric field (DCEF) was studied in an experiment on 16 sexually mature white rats weighing from 190 to 250 g, by causing them thermal burns using a special device. The area of the simulated burn was 8–10 % of the rat body surface, depending on its size. The depth of the lesion corresponded to IIIA-B degree burns according to O. V. Vyshnevsky (superficial and deep dermal burns). Galvanization of the damaged area was performed under anesthesia from the 3rd day using the device «Stream-1» with a direct current density of 0.04–0.05 mA/cm2 for 30 minutes. Behavioral reactions of animals, dynamics of weight loss, features of the wound process in the area of thermal damage were evaluated. Histological and bacteriological examination of wounds was performed for 2–3, 6–7, 13–14, and 19–21 days after modeling of burns.&#x0D; Results and discussion. The use of galvanization of burn wounds contributed to the activation of demarcation and cleaning processes in the damaged area, accelerated reparative regeneration, reduced microbial contamination of the wound surface. Thus, the optimization of the wound process was achieved, which was reflected in the timing of healing of the affected areas.&#x0D; Conclusions. As a result of an experimental study, it was found that DCEF has a beneficial effect on the wound process in the case of superficial and deep dermal thermal burns.

Prevalence and investigations of bacterial contamination in dental healthcare associated environment

Microbial contamination of medical substrate surface of dental parts touched or exposed to blood and saliva of patients can act as a reservoir for pathogenic bacteria, resulting in cross-contamination. For this reason, presence of oral microorganisms in dental clinics is a major source of dental contamination and infection worldwide. The work described here aimed to determine the presence of bacteria on variety of dental clinic surfaces including a dental chair arm rest, a sink/faucet, the floor beneath a dental chair; a towel dispenser, handles connected to a light and to an instrument table; dental record paper; an X-ray viewer and finally, a bench and head-rest in five separate departments (pediatric dentistry, implant, dental prosthetics, oral medicine and restorative dentistry) of the King Saud University Dental Hospital, both before and after patient treatment. The isolation and identification of bacterial colonies was achieved using a range of methods such as using a Vitek2 automated system. The results showed that all surfaces in different departments were contaminated with bacteria, most notably in the Implant Department, while much less bacterial contamination was reported in the Department of Oral Medicine. The most commonly isolated bacteria were species of, Staphylococcus, Streptococcus, Pseudomonas, Bacillus and Micrococcus.

Investigations on the Efficacy of Ozone as an Environmental Sanitizer in Large Supermarkets.

Awareness of the importance of the microbial contamination of air and surfaces has increased significantly during the COVID-19 pandemic. The aim of this study was to evaluate the presence of bacteria and fungi in the air and on surfaces within some critical areas of large supermarkets with and without an ozonation system. Surveys were conducted in four supermarkets belonging to the same commercial chain of an Apulian city in June 2021, of which two (A and B) were equipped with an ozonation system, and two (C and D) did not have any air-diffused remediation treatment. There was a statistically significant difference in the total bacterial count (TBC) and total fungal count (TFC) in the air between A/B and C/D supermarkets (p = 0.0042 and p = 0.0002, respectively). Regarding surfaces, a statistically significant difference in TBC emerged between A/B and C/D supermarkets (p = 0.0101). To the best of our knowledge, this is the first study evaluating the effect of ozone on commercial structures in Italy. Future investigations, supported by a multidisciplinary approach, will make it possible to deepen the knowledge on this method of sanitation, in light of any other epidemic/pandemic waves.

Evaluation of the efficacy of antimicrobials against pathogens on food contact surfaces using a rapid microbial log reduction detection method

Microbial contamination of food contact surfaces in food processing industries is a significant health hazard. Evaluating the efficacy of sanitizing agents used during food processing is essential to ensure public health and safety. This study describes an optical screening method using an oCelloScope to quantify the number of surviving bacterial cells, expressed as microbial log reduction (MLR), after antimicrobial treatment. We tested the efficacy of two sanitizing agents, sodium hypochlorite and benzalkonium chloride, against desiccated cells of three pathogens, S. Enteritidis, E. coli O157: H7, and L. monocytogenes that are of concern on food processing surfaces. Stainless steel slides were used to mimic commercial food processing surfaces. Bacterial cells were desiccated at 75% relative humidity (RH) before antimicrobial treatment on stainless steel surfaces, and survivor levels were analyzed via plate counts to calculate MLR. These were compared to MLR values generated using the oCelloScope. For analysis of MLR using the oCelloScope, cells were desiccated at 75% RH on polystyrene microtiter plates, treated with antimicrobials, and surviving cell numbers were analyzed. Our results show that MLR values of treated desiccated cells calculated using the BCA algorithm of the oCelloScope were comparable to the values generated using the traditional plate count assay for the same concentration and treatment duration of the antimicrobials against all the tested pathogens. MLR could not be calculated for a non-lytic antimicrobial (curcumin and UV-A irradiation) against E. coli O157:H7, however, modified growth curves demonstrated an antimicrobial effect of curcumin and irradiation treatment. The results indicate that this method can be used for rapid screening of MLR of lytic antimicrobial compounds. Quantification of MLR using the oCelloScope is an effective tool to rapidly identify appropriate antimicrobial treatments and can be used to study novel antimicrobial compounds in the future.

Do the differences in egg contamination, penetration, and resistance against microorganisms among the hen genotypes exist?

Abstract The aim of this study was to evaluate and compare the impact of genotype and storage conditions (temperature and time) on microbiological contamination and eggshell quality. There were four genotypes of laying hens used, Czech Golden Spotted (CGS), Greenleg Partridge (GP), White Leghorn (WL) and commercial hybrid (CH) hens were included. After collection, the eggs were divided equally into five groups according to the storage time (0, 14, 28 days) and temperature (5 and 20°C). The microbiological analysis included counting of colonies forming units (CFU) of Escherichia coli (EC), Enterococcus (ENT) and total number of microorganisms (TNM) on eggshell surface, eggshell membranes and in thin albumen. The analysis of eggshell quality included the determination of eggshell proportion (SP), thickness (ST), strength (SST), index (SI) and surface (SS). Moreover, egg weight (EW) and egg weight loss (EWL) were determined. The significant effect of genotype was found in contamination of eggshell by EC, ENT and TNM, eggshell membranes by TNM and albumen by EC (all P≤0.05). The significantly lowest contamination of eggshell from EC was in eggs from the WL hens (4.42 log CFU/eggshell), while from ENT was in eggs from the CGS hens (1.22 log CFU/eggshell) and from the WL hens (1.40 log CFU/eggshell). The lowest incidence of TNM was also detected in eggs from the WL hens (5.03 log CFU/eggshell). Statistically the lowest contamination of eggshell membranes by TNM was found in eggs from the WL (0.12 log CFU/eggshell membranes) and CH hens (0.15 log CFU/eggshell membranes). Regarding the effect of genotype, the GP (not detected) and WL (not detected) hens had eggs with statistically the lowest occurrence of EC bacteria in albumen. Regarding the EW and eggshell quality, all the parameters were significantly affected by the genotype (P≤0.0001). Also EWL was significantly (P≤0.05) affected by genotype (after 14, 21 and 28 days of storage). There were found to be significant differences of microbial contamination of egg surface among observed hen genotypes. The penetration of selected microorganisms was also significant in contamination of eggshell membranes by TNM and in contamination of albumen by EC.

Low risk for microbial contamination of syringe and tube feeding bag surfaces after multiple reuses with home blenderized tube feeding.

Guidelines for the reuse of enteral tube feeding (ETF) equipment guidelines are limited to manufacturer recommendations. ETF equipment reuse studies are needed as the enteral population has increased, along with blenderized tube feeding (BTF). This experiment tested microbial contamination of a reusable gravity feeding bag and syringe after 15 BTF reuses and cleanings. Eight bags and syringes were filled with the BTF, held at room temperature for 20 min, and then emptied, washed, and air dried. After the last air drying, the inner surfaces of the bag and syringe were swabbed, and aerobic microbial counts were performed using serial dilutions and plate counts. The microbial counts for all syringes and six bags were <1 colony-forming unit (CFU)/cm2 ; one bag was <5 CFU/cm2 and one bag was 12.5 CFU/cm2 . No legal guidelines for surface cleanliness exist for the food sector. Several studies propose a safe microbial level to be <2.5 CFU/cm2 , and the European Commission recommended <10 CFU/cm2 . Based on these proposed guidelines, microbial counts of all syringes and seven bags were within the proposed guidelines, except for one bag just above 10 CFU/cm2 . The feeding bag used in this study may be used multiple times for BTF with a reduced risk of microbial contamination when manufacturer's cleaning guidelines are followed. Although bolus tube feeding is an off-label use for syringes, they are frequently used for BTF, and in this study the cleaning after 15 uses over 5 days was effective to reduce microbial counts.

DISINFECTION OF MARKETABLE EGGS BY PLASMA-CHEMICALLY ACTIVATED AQUEOUS SOLUTIONS

Microbiological purity of raw materials and finished products is one of the most important factors of food safety. The acceptable level of microbiological contamination is provided by a set of sanitary and hygienic techniques in the course of manufacturing, selling, and consuming food products. It has been suggested that eggs should be disinfected by treating them with plasma-chemically activated aqueous solutions in order to reduce microbial contamination of the egg surfaces and remove salmonella from them. The surface of eggs is disinfected with aqueous solutions activated by non-equilibrium contact plasma with the different time of activation of these solutions. Plasma-chemically activated aqueous solutions act as high-quality disinfectants. They contain an active substance (hydrogen peroxide) with the concentration of 100 to 700 mg/l, and have pronounced antiseptic properties. The studies have revealed that with the use of plasma-chemically activated aqueous solutions as a disinfectant, the number of bacteria and fungi on the eggshell is significantly reduced. For example, E. coli and S. Enteritidis were not found in samples at the peroxide concentration as high as 100 mg/l, while the total bacterial contamination and pathogenic microflora under study (E. сoli, Asp. fumigatus, S. Enteritidis) were absent at 300 mg/l concentration of peroxides. Besides, our research included bacteriological studies of marketable eggs in storage. Thus, plasma-chemically activated aqueous solutions with the peroxide concentration 300 mg/l, besides destroying the pathogenic microflora completely (as evidenced by the total absence of QMAFAnM, CFU/cm3, S. enteritidis, E. coli, Asp. fumigatus in the studied samples), had a long-term disinfection effect: no pathogenic microflora appeared on the surface of the eggs within a month. This will allow extending the shelf life of marketable eggs. The studies of microbiological parameters of the dirty eggshells treated with plasma-chemically activated aqueous solutions have shown that the 400 mg/l concentration of peroxides allows getting rid of coliform bacteria, staphylococci, salmonella, spore-forming microflora, which makes a product saleable. The outward appearance of raw materials improves as well, which indicates a wide range of applications of the proposed technology of egg surface disinfection.

Exposure and Health Effects of Bacteria in Healthcare Units: An Overview

Healthcare units consist of numerous people circulating daily, such as workers, patients, and companions, and these people are vehicles for the transmission of microorganisms, such as bacteria. Bacteria species may have different allergenic, pathogenic, infectious, or toxic properties that can affect humans. Hospital settings foment the proliferation of bacteria due to characteristics present in the indoor hospital environment. This review article aims to identify the potential health effects caused by bacterial contamination in the context of healthcare units, both in patients and in workers. A search was carried out for articles published in PubMed, Web of Science and Scopus, between 1 January 2000 and 31 October 2021, using the descriptor hospital exposure assessment bacteria. This bibliographic research found a total of 13 articles. Bacteria transmission occurs mainly due to the contact between healthcare workers and patients or through the handling of/contact with contaminated instruments or surfaces. The most common bacterial contaminants are Escherichia coli, Pseudomonas aeruginosa, Staphylococcus spp., Staphylococcus aureus and Micrococcus luteus, and the principal health effects of these contaminants are hospital-acquired infections and infections in immunocompromised people. A tight control of the disinfection methods is thus required, and its frequency must be increased to remove the microbial contamination of wards, surfaces and equipment. A better understanding of seasonal variations is important to prevent peaks of contamination.