The effect of cold chain disruption on the microbiological profile of chilled chicken meat.

This study evaluates the influence of inadequate transport conditions on the microbiological quality of chilled chicken meat packaged in plain and modified atmosphere packaging (MAP). The experiments simulated the temperature increase during sample transport to 8, 11, 14, 17, 20, and 25°C with exposure times of 1, 2, 3, and 4 h. Aerobic plate count (APC), psychrotrophic microorganisms count (PMC), ß-D-glucuronidase-positive Escherichia coli, and Salmonella spp. were evaluated immediately after the exposure to the elevated temperature (0 h), 3 h, and 24 h after the return to the temperature of ≤4°C. The upper acceptable limits for APC and PMC were set for each combination of investigated chicken meat and packaging type, taking also the initial bacterial condition into account. Chilled chicken breast samples in plain packaging exceeded the APC limits in 16 cases and PMC limits in 20 cases when exposed to temperatures of >4°C, while only 2 MAP samples exceeded APC limits and 8 samples PMC limits, respectively. In chicken legs, 8 samples in plain packaging exceeded the APC limits and 15 the PMC limits, while 12 samples in MAP exceeded the APC limits and 19 the PMC limits. In 402 samples (31.9%) in which the presence of E. coli was detected, its amount ranged from 1.70 to 3.65 log CFU.g-1. It was more commonly detected in chicken legs (255 of 630; 40.5%) than chicken breasts (147 of 630; 23.3%) but was not related to exposure temperature, exposure time, or time until examination. The presence of Salmonella spp. was not detected in any of the samples. Data acquired in the presented study will be used in the development of software helping the national supervisory authorities in the Czech Republic to evaluate whether inadequate transport of samples to analytical laboratories could have affected the microbiological profile of the sample.

Quality Characterization of Honeys from Iraqi Kurdistan and Comparison with Central European Honeys.

The main objective of this work was to determine the significant physicochemical and bioactive parameters of honeys originating from Iraqi Kurdistan. For this purpose, honey samples (n = 16) were taken directly from Kurdish beekeepers from different places of Dohuk and Erbil Governorate in 2018 and 2022. The following parameters were analyzed: moisture content, electrical conductivity, diastase activity, hydroxymethylfurfural content, pH, free acidity, content of saccharides, total phenolic content, total flavonoid content, color, color intensity and DPPH, FRAP. Another objective of this work was to compare the properties of Kurdistan honeys with the requirements of European Union law and with the honeys of Central Europe. A total of 48 honey samples were included in the comparison. It was detected that the honeys produced in Iraqi Kurdistan met the strict quality criteria set by European law, which is important information for local beekeepers and experts in relation to honey production and an opportunity to set local limits of honey quality. Despite the different climatic and topographical conditions, the available flora, and the different species of bees, the properties of Iraqi Kurdistan honeys were similar to the properties of honeys from the Czech and Slovak Republics.

Dairy Cows' Udder Pathogens and Occurrence of Virulence Factors in Staphylococci.

This study investigated 960 Slovak and Czech spotted cattle from four different conventional (non-organic) dairy herds located in Eastern Slovakia and Czechia during early lactation (14-100 days after calving). Dairy cows were examined clinically; milk from fore-stripping of each udder quarter was subjected to sensory examination and assessed by the California mastitis test (CMT), and laboratory analyses of bacterial pathogens in milk, including virulence factors, were conducted. Positive CMT scores (1-3) for one or more quarters were detected in 271 (28.2%) of the examined animals. Out of 230 infected milk samples, representing 24.0% of all dairy cows, staphylococci (59.1% of positive findings) were the most commonly isolated organisms, followed by E. coli (11.3%), streptococci Str. uberis (9.1%) and Str. agalactiae (3.4%), and enterococci (6.1%). From 136 isolates of S. aureus (38 isolates) and non-aureus staphylococci (NAS; 98 isolates), virulence factors and their resistance to 14 antimicrobials were detected using the disk diffusion method, with PCR detection of the methicillin resistance gene, mecA. An increased incidence of clinical and chronic forms of mastitis has been reported in mastitic cows in which staphylococci, especially S. aureus and NAS (S. chromogenes, S. warneri, and S. xylosus), have been detected and compared to other isolated udder pathogens. From those species, S. aureus and isolates of NAS mentioned above showed multiple virulence factors that are more likely to hydrolyze DNA, hemolysis, produce gelatinase and biofilm, and have multi-drug resistance as compared to other less virulent staphylococci. Generally, the isolated staphylococci showed 77.2% resistance to one or more antimicrobials, in particular to aminoglycosides, ß-lactams, macrolides, or cephalosporins. Isolates that showed the ability to form a biofilm were more resistant to more than one antimicrobial than isolates without biofilm production. Multi-drug resistance to three or more antimicrobial classes was recorded in 16 isolates (11.7%), and the presence of the mecA gene was also confirmed in two isolates of S. aureus and two species of NAS.

Effect on Benzoic Acid Production of Yoghurt Culture and the Temperatures of Storage and Milk Heat Treatment in Yoghurts from Cow, Goat and Sheep Milk.

Yoghurts from cow, goat and sheep milk were produced and stored under defined conditions to monitor the influence of various factors on the benzoic acid content as determined by Ultra High Performance Liquid Chromatography (UHPLC). The highest level of benzoic acid was found in sheep yoghurt (43.26 ± 5.11 mg kg-1) and the lowest in cow yoghurt (13.38 ± 3.56 mg kg-1), with goat yoghurt (21.31 ± 5.66 mg kg-1) falling in between. Benzoic acid content did not show statistically significant variation until the second and third weeks of storage, and the dynamics of this variation varied depending on the type of yoghurt. The yoghurt culture containing different strains of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus also affected the contents of benzoic acid. Further, the different storage temperatures (2 and 8 °C) as well as the temperatures used to milk heat treatment before yoghurt production (80, 85 and 90 °C) affected the amount of benzoic acid in different types of yoghurts.

Effect of preservatives on the shelf-life and sensory characteristics of pasteurized liquid whole egg stored at 4°C.

The study focused on the effects of traditional (benzoate-sorbate and triphosphates) and alternative (nisin, Laktocid, Defence JB, and Galimax Flavor) food preservatives on the microbiological quality and sensory properties of pasteurized liquid whole eggs (LWE). The LWE samples with the addition of a test preservative and a control were stored at 4°C for 45 D. The selected microbiological parameters, sensory attributes, and color space parameters were determined. The results were statistically analyzed by means of factorial ANOVA, followed by the Tukey post hoc test. The multivariate method of principal component analysis based on the correlation matrix was employed to assess the relationships between pH and sensory characteristics of LWE. Total plate counts at the end of storage differed significantly, being the lowest in samples with benzoate-sorbate (1.69 ± 0.12 log cfu.g-1) and Laktocid (2.12 ± 0.12 log cfu.g-1). The final counts of lactic acid bacteria on day 45 were lower in the samples with benzoate-sorbate, triphosphates, nisin, and Laktocid (maximum 1.01 ± 1.44 log cfu.g-1). The amounts of yeasts at the end of storage did not differ among samples with different preservatives; none were detected in any samples with the exception of Defence JB (1.28 ± 1.90 log cfu.g-1). The lowest final mold count was observed in LWE with Laktocid (0.92 ± 1.29 log cfu.g-1). In conclusion, Laktocid showed great potential as a preservative; it had however a negative impact on pH value and the sensory properties of LWE.

Expression of growth-associated protein 43 in the skin nerve fibers of patients with type 2 diabetes mellitus.

The growth-associated protein 43 (GAP-43) is known as a marker of regenerating nerve fibers and their continuous remodeling in the adult human skin. The purpose of this pilot study was to investigate a possible role for GAP-43 in the detection of the early stages of small-fiber neuropathy in patients with type 2 diabetes mellitus (DM2) as compared with a well- established and validated parameter - intra-epidermal nerve fiber density (IENFD) of protein gene product 9.5 (PGP 9.5) immunoreactive intra-epidermal C fibers. In a group of 21 patients with DM2 within three years of diagnosis (13 men, 8 women; mean age 53.9±12.8; range 30-74) and a group of 17 healthy volunteers (8 men, 9 women; mean age 55.8±8.5; range 45-70 years), skin punch biopsies were taken from a distal calf and double immunostained with both PGP 9.5 and GAP-43. In healthy controls, 96.8% of 629 PGP 9.5 immunoreactive fibers were immunostained with GAP-43; the proportion of PGP 9.5 intra-epidermal nerve fibers immunoreactive for GAP-43 in control subjects ranged from 86.5 to 100%. In DM2 patients, IENFD was significantly lower compared to controls (median, 1.5 vs. 11.2/mm; p<0.001). The proportion of GAP-43 immunoreactive intraepidermal nerve fibers was significantly lower in DM2 patients compared to healthy controls (73.6% of 337 PGP 9.5 positive fibers; p<0.001); ranged from 0 to 98.1%. In conclusion, these results show that impaired regeneration of intra-epidermal C fibers in the early stages of type 2 diabetes mellitus, as indicated by GAP-43, might be a marker of incipient diabetic neuropathy.

Etiology of small-fiber neuropathy.

The aim of this study was to evaluate the etiology in a group of 84 patients with painful sensory neuropathy with predominant small-fiber dysfunction (54 men and 30 women, median: 58; range: 25-83 years) recruited from a population of the South Moravian region of the Czech Republic. Involvement of small nerve fibers was verified by abnormal thermal thresholds and/or reduced intraepidermal nerve fiber densities. Motor signs or symptoms or significant clinical signs of sensory large-fiber involvement were exclusionary; 33 patients, however, had sensory nerve conduction abnormalities. For comparison, the prevalence of risk factors was assessed in a group of 47 asymptomatic age- and sex-matched controls (30 men and 17 women, median: 59; range: 29-85 years). The multivariate regression model disclosed that diabetes mellitus (odds ratio [OR] = 4.08), chronic alcoholism (OR = 5.31), and serum cholesterol levels (OR = 4.51) were the only parameters independently associated with small-fiber involvement. No possible etiology was detected in 19 patients (22.6%). In conclusion, the spectrum of risk factors and proportion of idiopathic cases in geographically defined small-fiber polyneuropathy sample is similar to that referred in large-fiber polyneuropathy.