Acta Microbiologica Bulgarica

115-131

Authors: Jevšnik M., Raspor P.

Currently, food safety is managed through the HACCP system, and different good practices and food safety standards at different levels in food supply chain. The impact of food safety culture on the food sup¬ply chain is discussed at different levels and the realisation of it is achieved by various actors in complex food networks. Innovative approaches in the food supply chain have a positive impact by raising the level of employee qualifications and motivation to work according to the principles of food safety. The food business operator or person that is responsible for food safety is a key factor in identifying weaknesses in food safety, changing entrenched habits of employees, and introducing innovative approaches to effectively and rapidly respond to changes in the internal and external environments. This can build a new dimension of food safety, the so-called food safety culture, which is based on ethics in the field of food safety. As has been shown, the current maintenance of food safety in the food supply chain can easily break down, but the introduction of food safety culture can manage this issue and enhance food safety activities in food supply chains.

139-144

Authors: Al-Rawe A., Suleiman A. A.

Globally, cancer has been estimated to cause about 13% of all deaths in the world, especially in de¬veloping countries. Cancer cells are abnormal cells that disrupt the process of cell division, and there are more than 100 types of cancer. The diagnosis of cancer is still the most important factor in the success of cancer treatment. Treatment strategies of cancer may include radiation, chemotherapy, and surgery. This study was conducted to estimate microbiota counts in cancer patients, finding a method for detection and treatment follow up. Lactobacillus and Bifidobacterium counts were determined by qPCR depending on the standard curve from known bacterial counts obtained from probiotics. The main results of this study showed that the Lactobacillus count significantly increased in newly diagnosed cancer patients, while the count of Bifidobacterium decreased compared to the control. Also, chemotherapy led to a decrease in both bacteria counts, which may suggest supporting chemotherapy with probiotics.

153-162

Authors: Afolabi F. T., Ayodele E. O.

This study compared the yields of bioethanol from the fermentation of pretreated cassava peels using yeasts isolated from palm wine, and a pretreatment method with methanol + acid before solid-state fermen¬tation of cassava peels using Trichoderma reesei for 5 days optimally yielded 1.78 g/mL of reducing sugar. The hydrolysate was fermented for bioethanol production using Saccharomyces cerevisiae and Candida tropicalis. S. cerevisiae performed optimally at 30oC, pH 4.5, and produced ethanol with a concentration of about 40.72 g/L, while C. tropicalis produced 29.90 g/L of ethanol concentration at 35oC, and pH 5. Both yeast isolates took the same fermentation time of 96 h. In conclusion, cassava peels are agricultural waste that is a degradable material suitable to produce simple reducing sugars, which can be fermented by yeast to produce bioethanol. The yield of ethanol was higher for S. cerevisiae than C. tropicalis.

75-78

Authors: Savov, E., Kovachka, K., Trifonova, A., Kioseva, E., Strateva, T.

Intestinal carriage of extended spectrum β-lactamase Enterobacteriaceae (ESBL-E) and carbap¬enemase-producing Enterobacteriaceae (CPE) can persist for a long time (Huttner et al., 2019). Multi¬drug-resistant Acinetobacter baumannii and Pseudomonas aeruginosa and their intestinal carriage is also a big problem, because studies in the last years have shown that the colonization with multidrug-resistant Gram-negative bacteria (MDR-GNB), especially in immunocompromised patients, increases the risk of infections (Tacconelli et al., 2019). Therefore, the evaluation of decolonization regimens with oral antibi¬otics and faecal microbiota transplantation (FMT) used for eradication of MDR-GNB in the gut is of great importance in reducing morbidity and mortality in these patients.

90-95

Authors: David, O. M., Adelowo, O. O., Theophilus, O., Adetan, O. N., Ojo-Bola, T., Owabumoye, J. B., Moroa, D. D.

Pichia kudriavzevii is commonly used in food processing, its association with human infection is very rare. In the few cases where it has been reported, it is rarely present in healthy individuals. This study investigated the incidence of Pichia kudriavzevii among patients on catheter in a tertiary institution in Ekiti State. A structured questionnaire was used to collect demographic data of the patients. Fifty-six non-repeat catheterized urine samples were collected from consented patients and both pathogenic factors and antifun¬gal resistance were determined among the Pichia kudriavzevii isolated. Out of the 56 urine samples tested, 15 (26.8%) were positive for P. kudriavzevii while 31 (73.2%) showed growth of other fungi, mostly of the genus Candida. Out of the antifungal agents tested against P. kudriavzevii, ketoconazole [n=11 (73.3%)] was the most effective followed by clotrimazole [n=7 (46.7%)] and nystatin [n=6 (40%)]. According to the outcomes of the present study, P. kudriavzevii appears to be associated with urinary catheter and with many virulence factors. The isolates were also resistant to first-line antifungal drugs in addition to the virulence factors. This yeast may emerge as another fungal pathogen especially among immunocompromised.

100-103

Authors: Villegas, J. A. A., Rodriguez, M. I., Rodriguez, S. P., J. Gutierrez, A. G.

The objective of this study was to identify strains of Escherichia coli producing extended spectrum beta-lactamases (ESBL) in urine cultures and to evaluate the patterns of resistance to certain antibiotics used in clinical practice as treatment of choice in the Valley of Toluca, Mexico. One hundred and fifty-five urine samples were obtained from people in the Toluca Valley, Mexico, under the necessary hygiene con¬ditions, 100 ml used to identify the pathogen and its resistance patterns were collected from each sample through an automated WalkAway method. In order to determine ESBL, a double disk technique was used. Nineteen ESLE-producing strains of E. coli were obtained, of which 100% showed resistance to ampicillin and cephalosporins, to tetracycline 93.75% resistance, levofloxacin 87.5% and ciprofloxacin 81.25%, and sensitivity of 100% to amikacin and carbapenemics. In conclusion, antibiotic resistance represents a major health problem. As the present study shows, ampicillin is a drug of choice for urinary tract infectioncaused by E. coli, but in the Toluca Valley the resistance to this antibiotic is 100% in ESBL-producing strains, which also show high resistance patterns to cephalosporins, quinolones, tetracycline and trimethoprim with sulfamethoxazole.

108-109

Authors: Akhtar, N., Nawaz, F., Idnan, M.

The main purpose of this letter is to raise concerns about the imminent spike in Covid-19 infection cases in Pakistan during the upcoming event of Eid Ul Adha, 2020, due to mass gathering of people in the cattle markets, especially from asymptomatic coronavirus carriers. As Pakistan is already facing insur¬mountable difficulties in managing Covid-19 due to its limited healthcare infrastructure, a more severe coronavirus-19 outbreak is expected in the post-Eid Ul Adha days, especially in big cities like Lahore, Karachi and Islamabad, posing a new challenge for the authorities.

43-44

Authors: Mayer, F.

In recent years more people die each year from cardiovascular diseases (CVDs) than from any other cause and 17.7 million people died from CVDs in 2015, representing about one third of all global deaths ac¬cording to the WHO. Streptokinase is a thrombolytic agent with systemic fibrinolytic effect. It is a non-en¬zymatic protein produced by β haemolytic streptococci and activates the fibrinolytic system indirectly. Streptokinase is used widely and routinely for treatment of acute myocardial infarctions. In this study strep¬tokinase gene from Streptococcus pyogenes C1 was cloned in pET28a vector and transferred to Escherichia coli BL21. Expressed protein was purified by Ni-NTA column and visualized with SDS-PAGE. Streptoki¬nase (SK) coding DNA fragment was amplified from S. pyogenes C1 genomic DNA by PCR. The amplifi¬cation products were inserted into the cloning and expression vector pET28a(+). Recombinant pET28a(+) plasmid with recSK gene were then introduced to E. coli BL21 (DE3) by electroporation. The streptokinase encoded by the plasmid pET28a(+) contains the mature streptokinase with the 6X histidine-tag.

53-58

Authors: Adeogun, O. S., David, O. M., Adesina, A. O., Babalola, T. O.

Hepatitis B virus (HBV) and Hepatitis C virus (HCV) infections cause chronic hepatitis in humans. The co-infections of these viruses with human immunodeficiency virus (HIV) have increased the burden, especially in the resource-poor nations of the world. In this study we determine the burden of HBV and/ or HCV with HIV among pregnant women attending selected General Hospitals in Ondo State, Nigeria. The sera of consented subjects were collected and screened for the presence of HBV using enzyme-linked Immunosorbent Assay (ELISA) kits while HIV was detected using WHO approved rapid kit and its confir-mation was done with Western blot assay. Out of two thousand, nine hundred ninety-eight (2.998) pregnant women screened, the numbers positive for HBV (HBsAg), HCV (antibody) and HIV (antibody) were 60, 54 and 28, respectively. The highest HIV seroprevalence was detected among women in the age group of 35- 39 years. The seroprevalence of co-infections HBV and HCV was 0.07 % while those of HIV and HBV, and HIV and HCV were 0.03 % each. None of the subjects had the three viruses. The difference in demographic characteristics of the study population in the study areas might explain the varying results observed in this study. Pregnant women should not only be screened for HIV but also for both Hepatitis B and C infections during their first ante-natal visit.

63-67

Authors: Shilev, S.

Arsenic is a common contaminant in soils, affecting soil microbiome and all soil organisms. The present study examined arsenate tolerance of two Saccharomyces cerevisiae strains isolated from contami¬nated soil. Their tolerance to sodium arsenate (AsV) was studied in a liquid medium for 24 hours, while the ability of the populations to reduce their intracellular arsenic content was subsequently investigated through kinetic studies of arsenate transport at 33.3, 133.2, and 266.4 μM of AsV. The dependence of tolerance on the efflux system was demonstrated by the use of amiloride hydrochloride, which is known as a suppressor of ion transport through the cell membrane. The maximum concentration tolerated by S. cerevisiae AS09 was found to be about 72.8% lower than that by the tolerant S. cerevisiae AS07. The influx and efflux of arsenate across the cell membranes of both strains were dependent on the concentration of metalloid in the medium and on the anion net balance. Both strains rapidly increased their internal As concentration to a maximum point, although only the tolerant strain was able to decrease it subsequently in all concentrations used. When the highest concentration was applied, the cells of the non-tolerant strain were found to be dead. When amiloride hydrochloride was used it was found that the tolerant cells behaved like sensitive cells, and at 266.4 μM the cells of both strains were found to be dead, because the extrusion of the toxic anion was interrupted. Kinetic differences in arsenate transport through the cell membrane explain the different degrees of tolerance of the studied strains.

3-8

Authors: Galabov, A.S., Galabov, S.A.

The review presents the basic data on the chemical compounds manifesting pronounced activity against SARS-CoV-2, the causative agent of the COVID-19 pandemic. The compounds are characterized with their chemical structure, and experimental anti-coronavirus activity in vitro (in cell cultures) and in vivo (in laboratory animals). The existing data on their clinical use in the treatment of patients with COVID-19, double-blind trials included, occupies an important place and are object of discussion on the therapeutic effectiveness of antivirals.

19-29

Authors: Krumova, E., Najdenski, H., Dishlijska, V., Abrashev, R., Stoyancheva, G., Gocheva, Y., Kostadinova, N., Miteva-Staleva, J., Spasova, B., Angelova, M.

The amount of waste generated on manned long-duration space missions away from Earth orbit creates the daunting challenge of how to manage the waste through reuse, rejection, or recycling. Microbial degradation, for both economic and ecological reasons, has become an increasingly popular alternative for the treatment of cellulose containing organic waste in the space stations. This approach offers several advantages: low energy, mild operation conditions, control on biological hazard of the wastes, etc. Fungi are the main cellulose-degrading microorganisms in the nature and their cellulolytic features are object of intensive studies. This review describes the ability of anaerobic, aerobic, and microaerophilic fungi to degrade organic wastes generated during manned space flight.