Evaluation of microbiological risks in cream as a raw material for buttermaking

The article presents the research results of studying the influence of various groups of microorganisms — coliform bacteria, lactic acid microorganisms, yeast, and spore bacteria — on the quality and storage capacity of cream used as a raw material for buttermaking. The objects of study were the following: cream as a raw material before and after pasteurization, as well as pasteurized cream seeded with testing cultures of various types of spoilage microorganisms. The samples were stored at temperature conditions of 30 ± 1 °C, 10 ± 1 °C, and 4 ± 2 °C. To evaluate the quality and storage capacity of cream used as a raw material, its microbiological and physicochemical indicators were determined by standardized methods: bacterial number, titratable acidity, indicators of oxidative spoilage of the fat phase. Organoleptic characteristics were evaluated in terms of taste, consistency and appearance. Research results have shown that the greatest microbiological risks during storage of cream used as a raw material are associated with lactococci, coliform bacteria and yeast. Microbiological risks caused by seeding of cream with thermophilic streptococcus, spore bacteria of the genus Bacillus and spore anaerobic microorganisms of the genus Clostridium are less significant, which is associated with the lack of development and metabolism of these groups of microorganisms at storage temperatures of 10 ± 1 °C and 4 ± 2 °C. At the same time, the reason for the rejection of cream contaminated with these testing cultures, at a storage temperature of 4 ± 2 °C, is primarily a decrease in organoleptic indicators, and at a temperature of 10 ± 1 °C — an excess in bacterial number.

Positive correlation between the number of bacteria in soybean tempeh with the bioactivity of its extract against enterotoxigenic Escherichia coli (ETEC) adhesion to eukaryotic cells

Bioactive oligosaccharides from soybean tempeh can inhibit the adhesion of enterotoxigenic Escherichia coli (ETEC) to intestinal cells, thus reducing the severity of ETEC-mediated diarrhea. Bacteria are also present in tempeh but there has yet been any report regarding their effect on the anti-adhesion bioactivity of tempeh. In this research, the bacterial number in tempeh was quantified and the anti-adhesion bioactivity of tempeh extract was determined using yeast agglutination assay. Statistical analysis showed a moderately (R = 0.69) significant positive correlation (P < 0.01) between the number of bacteria in tempeh and the anti-adhesion bioactivity of its extract. In conclusion, tempeh that contains more bacteria is more effective in inhibiting ETEC adhesion to eukaryotic cells. This could be due to a symbiosis between Rhizopus and bacteria in breaking down soy matrix polysaccharides to release bioactive oligosaccharides.

Effect of human secretory calcium-binding phosphoprotein proline-glutamine rich 1 protein on Porphyromonas gingivalis and identification of its active portions

The mouth environment comprises the second most significant microbiome in the body, and its equilibrium is critical in oral health. Secretory calcium-binding phosphoprotein proline-glutamine rich 1 (SCPPPQ1), a protein normally produced by the gingival epithelium to mediate its attachment to teeth, was suggested to be bactericidal. Our aim was to further explore the antibacterial potential of human SCPPPQ1 by characterizing its mode of action and identifying its active portions. In silico analysis showed that it has molecular parallels with antimicrobial peptides. Incubation of Porphyromonasgingivalis, a major periodontopathogen, with the full-length protein resulted in decrease in bacterial number, formation of aggregates and membrane disruptions. Analysis of SCPPPQ1-derived peptides indicated that these effects are sustained by specific regions of the molecule. Altogether, these data suggest that human SCPPPQ1 exhibits antibacterial capacity and provide new insight into its mechanism of action.

Detection of Bacterial Contamination of Some Traditional Frozen Fish in Some Local Markets in Tikrit City

This study was aimed to investigate bacterial contamination in frozen fish form samples collected from some local markets in several neighborhoods of Tikrit city. Thirty samples of frozen fish were collected for two types of fish common carp and fish fillet, laboratory bacterial isolation and diagnosis showed Staph. aurues samples constitute highest proportion of isolations which followed by Aeromonaus hydrophyla, E.coli, Psudomonas. Spp and Salmonella ( 7,6, 5 and 3) isolations. Bacterial number of isolations has been calculated where it showed a variant in number of bacterial colonies, Staph. aurues which recorded the highest rate in colonies number. Chemical analyses to estimate the amount of protein and fat showed 9.43, 7.31% of protein and 3.9, 8.66 % fat, so as to moisture was high in both carp and elephant fish 80.5, 75.72% and ash 2.31, 7% in carp and fish fillet, respectively. The results of current study shows there are an inverse relationship between both used fish in study and the moisture in the fish.

Smart Chimeric Lysin ClyC Loaded Alginate Hydrogel Reduces Staphylococcus aureus Induced Bone Infection

Staphylococcus aureus (S. aureus) is the most common cause of hospital and community-acquired infections. The current clinical treatment is limited by the emergence of drug-resistant strains. We previously developed a chimeric ClyC that effectively inhibited S. aureus strains. Nonetheless, an efficient delivery system to provide sustained release of ClyC to infected site is needed. Thus, we engineered a chimeric ClyC loaded alginate hydrogel (ClyC-AH) to improve the therapeutic outcomes against S. aureus. ClyC-AH retained the stability and activity of ClyC while providing a sustained release of ClyC and a continuous antibacterial effect against S. aureus. Compared to ClyC alone, the use of ClyC-AH was relatively safe, as there was no significant cytotoxicity to BHK-21 cells at a ClyC concentration≤250 μg/ml. Furthermore, in a S. aureus infected mouse model of osteomyelitis, ClyC-AH reduced bacterial burden in the femur and surrounding tissues, with a reduction of 2 log10 (CFU/ml) in viable bacterial number. Based on these results, hydrogel-delivered chimeric lysin ClyC provides a promising future in the S.aureus targeting therapy.

Distribution of Soil Microorganisms in Field under Potatoes due to Fertilizer and Organics

Background: Using organic manure derived from animal or vegetable matter is often associated with balanced crop production. The influence of organics and fertilizers on soil sustainability during cultivation of potatoes in field was studied. Methods: Vegetable experiment comprising 10 years (2011-2021), having a control variant (no fertilization), independent mineral, organics (compost) and their combination (50:50%). Changes in the amount and distribution of microbial groups in experimental variants and associated untreated controls were evaluated. Total bacterial number, spore-forming bacteria, fungi, nitrogen-utilizing bacteria and actinomycetes were assessed. Result: Applied organics and fertilizers had statistically proven a positive effect on growth parameters of potatoes. Organics and fertilizers supplied with mineral and foliar feeding registered taller plants with increased number of branches, number and mass of leaves and stem and root masses, compared to potatoes with organic and organic-mineral combination. Application of compost led to a significant increase in populations of all physiological groups of microorganisms excluding spore-forming bacteria and bacteria utilizing mineral nitrogen, which is a good indicator of increased soil microbial activity in respective treatments. Mineral fertilization had a positive effect on total number of bacteria and on absorption of mineral nitrogen. The treatment in variant (50:50 %) at rhizosphere soil was associated with organic manure application and at non-rhizosphere soil with mineral fertilizer.

Evaluation of Bacterial Reduction after Root Canal Shaping Using ProTaper Gold and WaveOne Gold Rotary Systems

Introduction The present study evaluated bacterial reduction promoted by the WaveOne system (Dentsply Maillefer, Ballaigues, Switzerland) and ProTaper Gold system (PTG; Dentsply Maillefer) in human extracted central incisors. Methods Sixty-two maxillary central incisors that were infected with Enterococcus faecalis (ATCC 51299) were sterilized with ethylene oxide for 21 days, and then root canal initial bacterial sample was collected with paper points and plated on M-Enterococcus agar. The specimens were randomly divided into two groups according to instrumentation: WaveOne Gold group (n = 30) and PTG group (n = 30). Each group was further subdivided into subgroup A (n = 15) where no activation of the irrigant was performed, and subgroup B (n = 15) where passive ultrasonic activation (PUI) was applied. The other two specimens without contamination were control asepsis. After instrumentation, samples were collected with the use of paper points. The bacterial reduction was calculated using colony-forming unit and quantitative real-time polymerase chain reaction. Data were collected and statistically analyzed. Results All techniques significantly reduced the number of bacteria in the root canal (p < 0.05), in which PTG showed superior bacterial reduction than WaveOne Gold (p > 0.05). The aseptic control group did not show any bacterial growth. PUI showed a significant bacterial reduction with the WaveOne Gold group. Conclusion It can be concluded that the single-file system, WaveOne Gold with the aid of passive ultrasonic irrigation, significantly reduce the bacterial number in the root canal similar to the multifile system, PTG.

In vivo oxygen measurement in cerebrospinal fluid of pigs to determine physiologic and pathophysiologic oxygen values during CNS infections

During infection and inflammation, a reduced oxygen level clearly affects cellular functions. Oxygen levels during CNS infections are unknown. Here we established and evaluated an in vivo measurement system to characterize the oxygen level in parallel with bacterial numbers (CFU/mL), the cell number and pH level inside the CSF of healthy compared to Streptococcus suis-infected pigs. The animals were anesthetized over a seven-hour period with isoflurane in air/oxygen at physiologic arterial partial pressure of oxygen. Oxygen levels in CSF of anesthetized pigs were compared to euthanized pigs. The detected partial pressure of oxygen in the CSF remained constant in a range of 47–63 mmHg, independent of the infection status (bacterial or cell number). In contrast, the pH value showed a slight drop during infection, which correlated with cell and bacterial number in CSF. We present physiologic oxygen and pH values in CSF during the onset of bacterial meningitis.

A Highly Active Chimeric Lysin with a Calcium-Enhanced Bactericidal Activity against Staphylococcus aureus In Vitro and In Vivo

Lysins, including chimeric lysins, have recently been explored as novel promising alternatives to failing antibiotics in treating multi-drug resistant (MDR) pathogens, including methicillin-resistant Staphylococcus aureus (MRSA). Herein, by fusing the CHAP (cysteine, histidine-dependent amidohydrolase/peptidase) catalytic domain from the Ply187 lysin with the non-SH3b cell-wall binding domain from the LysSA97 lysin, a new chimeric lysin ClyC was constructed with Ca2+-enhanced bactericidal activity against all S. aureus strains tested, including MRSA. Notably, treating S. aureus with 50 μg/mL of ClyC in the presence of 100 μM Ca2+ lead to a reduction of 9 Log10 (CFU/mL) in viable bacterial number, which was the first time to observe a lysin showing such a high activity. In addition, the effective concentration of ClyC could be decreased dramatically from 12 to 1 μg/mL by combination with 0.3 μg/mL of penicillin G. In a mouse model of S. aureus bacteremia, a single intraperitoneal administration of 0.1 mg/mouse of ClyC significantly improved the survival rates and reduced 2 Log10 (CFU/mL) of the bacterial burdens in the organs of the infected mice. ClyC was also found stable after lyophilization without cryoprotectants. Based on the above observations, ClyC could be a promising candidate against S. aureus infections.